Forecast Discussions mentioning any of "HRRR" "RR" "RUC13" "RUC" received at GSD on 01/04/12


AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
400 PM EST Mon Jan 2 2012 ...Arctic airmass to arrive tonight and last through Wednesday morning... ...Freeze warning and wind chill advisory tonight... .SYNOPSIS... 20Z water vapor and H4 RUC analysis shows a high amplified northern stream upper level pattern across North America. This flow consists of high amplitude ridging over the inter-mountain west...followed downstream by an impressive and still sharpening trough over the eastern half of the nation. Upstream from our area we see a strong 140+ knot upper level jet propagating down the backside of the upper trough. This energy will help to further amplify the base of the trough into our region during the evening hours and bring about significant changes to our local weather. At the surface, The cold front from Sunday evening is now well south of our area across the southern FL peninsula. A cooler and drier airmass has arrived in its wake with temperatures in the 50s, as opposed to Sunday`s 70s. Winds are also rather gusty with a tight gradient between the front and a strong 1040+mb surface high building across the mid-section of the country. The wind advisory remains in effect for the entire region through the day as efficient diurnal mixing has allowed stronger winds a few thousand feet aloft to mix down to the surface. Wind gusts around 25mph have been common across the region thus far this afternoon. && .SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)... Tonight, Big changes occur this evening as the upper jet max, and associated shortwave impulse rotate across the southeastern states. This impulse will push an secondary arctic cold front quickly across the forecast area. In the wake of this front, the "flood-gates" in terms of cold air will open. 850mb temps are progged to plummet 8-10C over most areas between 00UTC and 06UTC. Temperatures at the surface will fall below freezing at most area by around 3-4AM and likely remain below freezing until several hours after sunrise. In fact, often with these overnight arctic cold frontal passages, we experience the lowest temperatures a hour or 2 after sunrise, as strong CAA advection overwhelms any early morning solar addition. Speaking of lows, we are looking for widespread mid/upper 20s, with upper 20s to around 30 at the immediate coast. Add in a steady NW wind and wind chills are expected to reach the upper teens in many locations around sunrise. Due to these expected wind chills, a wind chill advisory has been issued for all zones late tonight into early Tuesday morning, in addition to the freeze warning already in effect. Tuesday/Tuesday Night, A cold day on tap for the region. Although heights will be rising through the day as the upper trough exits to our east, this will be deceiving due to the shallow nature of the arctic airmass in place. 850mb temps which are impressively low around sunrise -6c to -10c will quickly rebound during the afternoon/evening hours, however the recovery is much slower below this level leading to a somewhat inverted thermal profile by the second half of the day. This profile will hinder efficient diurnal mixing and keep our temps quite cold. Have once again undercut the MAV as statistical guidance often has difficulty with these types of airmasses. With some CAA still ongoing early in the morning and the low sun angle, temperatures will be very slow to come up during the mid/late morning. We will eventual recover to chilly readings in the lower 40s north and perhaps mid 40s south, but with a steady NW wind, wind chills are likely to remain in the 30s through much (if not all) of the day. Strong 1030+mb high pressure will quickly build over-top the region Tuesday evening. This strong high will work with already cold early evening temps and very dry low level air to produce near ideal radiational cooling conditions. Expecting temps to fall quite rapidly in the hour or two around sunset, allowing temps to fall below freezing early in the night. Temperatures will then remain below freezing for an extended duration for many locations. The average time below freezing looks to be around 8-10 hours, however a few colder spots may see 12+ hours below 32. By sunrise Wednesday morning, low temps are forecast to reach widespread upper teens to lower 20s. Would not be surprised to see a few normally colder spots drop to the middle teens. On the other hand, locations along the immediate coast and more urbanized inland centers (like downtown Tallahassee) will see temps bottom out closer to the middle 20s. Wednesday/Wednesday Night, The thermal recovery will continue with high pressure remaining nearby through the day. After the very cold start to the morning, abundant sunshine should be able to climb our temps back into the lower 50 by the end of the afternoon. A weak shortwave impulse will push a subtle cold front toward the region Wednesday night, however this frontal passage will be little more than a wind shift and some slightly drier air in its wake. The night will still be cool, however the thermal ridge ahead of this trough should generally prevent any widespread freezing temperatures into early Thursday morning. && .LONG TERM (THURSDAY THROUGH NEXT MONDAY)... (Wednesday night through next Monday) The evolution of the large scale upper level pattern across the CONUS will continue to be dominated by a high persistent latitude negative anomaly just west of the Dateline, with ridging developing over the eastern Pacific. Downstream, a mean trough will extending from Canada to the southwest U.S., with another trough over the western Atlantic. There is some hint of retrogression in the pattern toward the end of the period in the 6-10 day guidance, and the latest ECMWF gives some support to this by dropping a vigorous short wave much further south and east over the lower Mississippi Valley early next week. Meanwhile, a series of short waves will move rapidly through the large scale pattern, and as always the devil is in he details. Will continue to favor the ECMWF for basic guidance, first of all because it fits my preconceived ideas, and also because it fits what I think should be the basic behavior of the short waves, given the larger scale pattern expected from teleconnections to the anomaly upstream in the northern Pacific. For the Tri-State Area, this translates to a fairly rapid moderation in temperatures following one more frosty morning on Thursday, as heights rise and the cold surface high weakens and shifts eastward, allowing the low level flow to become more southerly by the end of the week. Temperatures will return to near normal on Friday, and above normal through the rest of the period. An upper level short wave will move rapidly past the area on Thursday, pushing another rather diffuse and weakening frontal boundary southward over the Florida Peninsula, while leaving the boundary stalled over the western Gulf of Mexico. Heights rise rapidly across the southeast U.S. ahead of a short wave in the southern stream. This system is forecast to develop a wave along the front as it moves eastward on Friday and Saturday, and produces overrunning precipitation across the northern Gulf. The rapid warmup will preclude a chance for any frozen precipitation. Confidence remains a bit low on how just how much moisture will be available to this system, and for now will indicate only slight chance to lower end chance PoPs, though this could produce a more significant precipitation event for portions of the northern Gulf and southeast U.S. Finally, a very impressive short wave in the northern stream is forecast to dig southward into the lower Mississippi Valley Sunday and Monday. Keeping in mind the inherent uncertainties present at such a long time frame, especially given the current fast-moving progressive pattern, present indicators are that there could be sufficient return flow ahead of this system, along with good dynamic support for a potential severe event. Something to keep an eye on during the coming week. && .AVIATION... VFR conditions will prevail through the forecast period and beyond. Reinforcing cold front will push through the region this evening/overnight, sustaining n-nwly winds with strong afternoon gusts. This will be a dry front so no vsby or cig restrictions are expected. LLWS may be a problem for a couple of hours in the morning if surface winds lighten more than forecast, given the very strong nly winds just off the surface. && .MARINE... Northwest wind near advisory levels will increase later this evening with the passage of a strong cold front. Frequent gusts to gale force are expected for a period from late this evening into the early morning hours of Tuesday. These strong winds will result in very rough seas over the Northeast Gulf of Mexico. Winds and seas will begin to diminish Tuesday afternoon and Night as strong high pressure builds over the region. && .FIRE WEATHER... The coldest air of the season will continue to sink into the region with very dry conditions and brisk north winds prolonging Red Flag conditions the rest of today, as well as for our Florida counties Tuesday. Region will likely see RH in the teens Tuesday with sustained northerly winds of 15+ mph and higher gusts. These winds may remain just below criteria in Alabama and Georgia, thus will maintain a watch across these areas Tuesday afternoon. On Wednesday, RH will remain in the teens to lower 20s, although winds will be much lighter and conditions may not support Red Flags with ERC/dispersions remaining below criteria. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 27 43 18 53 34 / 0 0 0 0 0 Panama City 29 46 28 54 43 / 0 0 0 0 0 Dothan 27 42 24 54 37 / 0 0 0 0 0 Albany 26 42 22 54 33 / 0 0 0 0 0 Valdosta 26 42 21 53 32 / 0 0 0 0 0 Cross City 26 45 18 54 34 / 0 0 0 0 0 Apalachicola 32 46 26 54 41 / 0 0 0 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...Red Flag Warning until 5 PM CST this afternoon for Coffee-Dale- Geneva-Henry-Houston. Freeze Warning from Midnight tonight to 8 AM CST Tuesday for Coffee-Dale-Geneva-Henry-Houston. Hard Freeze Watch from Tuesday evening through Wednesday morning for Coffee-Dale-Geneva-Henry-Houston. Wind Advisory until Midnight CST tonight for Coffee-Dale-Geneva- Henry-Houston. Wind Chill Advisory from 3 AM to 9 AM CST Tuesday for Coffee- Dale-Geneva-Henry-Houston. Fire Weather Watch Tuesday afternoon for Coffee-Dale-Geneva- Henry-Houston. GA...Red Flag Warning until 6 PM EST this evening for Baker-Ben Hill- Berrien-Brooks-Calhoun-Clay-Colquitt-Cook-Decatur-Dougherty- Early-Grady-Irwin-Lanier-Lee-Lowndes-Miller-Mitchell- Quitman-Randolph-Seminole-Terrell-Thomas-Tift-Turner-Worth. Freeze Warning from 1 AM to 9 AM EST Tuesday for Baker-Ben Hill- Berrien-Brooks-Calhoun-Clay-Colquitt-Cook-Decatur-Dougherty- Early-Grady-Irwin-Lanier-Lee-Lowndes-Miller-Mitchell- Quitman-Randolph-Seminole-Terrell-Thomas-Tift-Turner-Worth. Hard Freeze Watch from Tuesday evening through Wednesday morning for Baker-Ben Hill-Berrien-Brooks-Calhoun-Clay-Colquitt- Cook-Decatur-Dougherty-Early-Grady-Irwin-Lanier-Lee-Lowndes- Miller-Mitchell-Quitman-Randolph-Seminole-Terrell-Thomas- Tift-Turner-Worth. Wind Advisory until 1 AM EST Tuesday for Baker-Ben Hill-Berrien- Brooks-Calhoun-Clay-Colquitt-Cook-Decatur-Dougherty-Early- Grady-Irwin-Lanier-Lee-Lowndes-Miller-Mitchell-Quitman- Randolph-Seminole-Terrell-Thomas-Tift-Turner-Worth. Wind Chill Advisory from 4 AM to 10 AM EST Tuesday for Baker-Ben Hill-Berrien-Brooks-Calhoun-Clay-Colquitt-Cook-Decatur- Dougherty-Early-Grady-Irwin-Lanier-Lee-Lowndes-Miller- Mitchell-Quitman-Randolph-Seminole-Terrell-Thomas-Tift- Turner-Worth. Fire Weather Watch Tuesday afternoon for Baker-Ben Hill-Berrien- Brooks-Calhoun-Clay-Colquitt-Cook-Decatur-Dougherty-Early- Grady-Irwin-Lanier-Lee-Lowndes-Miller-Mitchell-Quitman- Randolph-Seminole-Terrell-Thomas-Tift-Turner-Worth. FL...Red Flag Warning until 6 PM EST /5 PM CST/ this evening for Calhoun-Central Walton-Coastal Bay-Coastal Dixie-Coastal Franklin-Coastal Gulf-Coastal Jefferson-Coastal Taylor- Coastal Wakulla-Gadsden-Holmes-Inland Bay-Inland Dixie- Inland Franklin-Inland Gulf-Inland Jefferson-Inland Taylor- Inland Wakulla-Inland Walton-Jackson-Lafayette-Leon-Liberty- Madison-South Walton-Washington. Red Flag Warning from 11 AM EST /10 AM CST/ to 6 PM EST /5 PM CST/ Tuesday for Calhoun-Central Walton-Coastal Bay-Coastal Dixie-Coastal Franklin-Coastal Gulf-Coastal Jefferson- Coastal Taylor-Coastal Wakulla-Gadsden-Holmes-Inland Bay- Inland Dixie-Inland Franklin-Inland Gulf-Inland Jefferson- Inland Taylor-Inland Wakulla-Inland Walton-Jackson- Lafayette-Leon-Liberty-Madison-South Walton-Washington. Freeze Warning from 1 AM EST /Midnight CST/ to 9 AM EST /8 AM CST/ Tuesday for Calhoun-Central Walton-Coastal Bay-Coastal Dixie-Coastal Franklin-Coastal Gulf-Coastal Jefferson- Coastal Taylor-Coastal Wakulla-Gadsden-Holmes-Inland Bay- Inland Dixie-Inland Franklin-Inland Gulf-Inland Jefferson- Inland Taylor-Inland Wakulla-Inland Walton-Jackson- Lafayette-Leon-Liberty-Madison-South Walton-Washington. Hard Freeze Watch from Tuesday evening through Wednesday morning for Calhoun-Central Walton-Coastal Bay-Coastal Dixie- Coastal Franklin-Coastal Gulf-Coastal Jefferson-Coastal Taylor-Coastal Wakulla-Gadsden-Holmes-Inland Bay-Inland Dixie-Inland Franklin-Inland Gulf-Inland Jefferson-Inland Taylor-Inland Wakulla-Inland Walton-Jackson-Lafayette-Leon- Liberty-Madison-South Walton-Washington. Wind Advisory until 1 AM EST /Midnight CST/ Tuesday for Calhoun- Central Walton-Coastal Bay-Coastal Dixie-Coastal Franklin- Coastal Gulf-Coastal Jefferson-Coastal Taylor-Coastal Wakulla-Gadsden-Holmes-Inland Bay-Inland Dixie-Inland Franklin-Inland Gulf-Inland Jefferson-Inland Taylor-Inland Wakulla-Inland Walton-Jackson-Lafayette-Leon-Liberty- Madison-South Walton-Washington. Wind Chill Advisory from 4 AM EST /3 AM CST/ to 10 AM EST /9 AM CST/ Tuesday for Calhoun-Central Walton-Coastal Bay-Coastal Dixie-Coastal Franklin-Coastal Gulf-Coastal Jefferson- Coastal Taylor-Coastal Wakulla-Gadsden-Holmes-Inland Bay- Inland Dixie-Inland Franklin-Inland Gulf-Inland Jefferson- Inland Taylor-Inland Wakulla-Inland Walton-Jackson- Lafayette-Leon-Liberty-Madison-South Walton-Washington. GM...Small Craft Advisory until 7 PM EST this evening for Apalachee Bay-Coastal waters From Ochlockonee River to Apalachicola FL out to 20 NM-Coastal waters from Suwannee River to Keaton Beach FL out 20 NM-Coastal waters from Apalachicola to Destin FL out 20 NM-Waters from Suwannee River to Apalachicola FL from 20 to 60 NM-Waters from Apalachicola to Destin FL from 20 to 60 NM. Gale Warning from 7 PM this evening to 8 AM EST Tuesday for Apalachee Bay-Coastal waters From Ochlockonee River to Apalachicola FL out to 20 NM-Coastal waters from Suwannee River to Keaton Beach FL out 20 NM-Coastal waters from Apalachicola to Destin FL out 20 NM-Waters from Suwannee River to Apalachicola FL from 20 to 60 NM-Waters from Apalachicola to Destin FL from 20 to 60 NM. && $$ SYNOPSIS/SHORT TERM/MARINE...MROCZKA LONG TERM...DUVAL AVIATION/FIRE WEATHER...EVANS
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1035 AM EST Mon Jan 2 2012 .UPDATE (Today through Tonight)... Previous forecast appears on track and no significant changes are anticipated. 15Z water vapor and H4 RUC analysis now showing a high amplified northern stream upper level pattern across North America. This flow consists of high amplitude ridging over the inter-mountain west...followed downstream by an impressive and still sharpening trough over the eastern half of the nation. KTLH sounding experienced technical problems this morning preventing a full sounding profile, however WV imagery and the crystal clear skies out the window suggest an already very dry column through a deep layer of the troposphere. Upstream from our area we see a strong 140+ knot upper level jet beginning to propagate down the backside of the upper trough. This energy will help to further amplify the trough this evening and bring about significant changes in our local weather. At the surface, The cold front from Sunday evening is now well south of our area across the southern FL peninsula. A cooler and drier airmass has arrived in its wake with temperatures in the 50s, as opposed to Sunday`s 70s. Winds are also rather gusty with a tight gradient between the front and a strong 1040+mb surface high building across the mid-section of the country. The wind advisory remains in effect for the entire region through the day as efficient diurnal mixing eventually allows stronger winds a few thousand feet aloft to mix down to the surface. As mentioned above, ongoing weak cold air advection will help keep temperatures in check this afternoon, and only anticipate highs in the lower/mid 50s north and mid/upper 50s south. Tonight, Big changes occur this evening as the upper jet max, and associated shortwave impulse rotate across the southeastern states. This impulse will push an secondary arctic cold front quickly across the forecast area. In the wake of this front, the "flood-gates" in terms of cold air will open. 850mb temps are progged to plummet 8-10C over most areas between 00UTC and 06UTC. Temperatures at the surface will fall below freezing at most area by around 3-4AM and likely remain below freezing until several hours after sunrise. In fact, often with these overnight arctic cold frontal passages, we experience the low temperatures a hour or 2 after sunrise, as strong CAA advection overwhelms any early morning solar addition. Speaking of lows, we are looking for widespread mid/upper 20s, with upper 20s to around 30 at the immediate coast. Add in a steady NW wind and wind chills are expected to reach the upper teens in many locations around sunrise Tuesday morning. Should these wind chill reading continue to be anticipated with the afternoon forecast package, a wind chill advisory will become necessary in addition to the freeze warning already in effect. && .AVIATION... (through 18Z Tuesday) VFR VFR conditions will prevail through the forecast period and beyond. Stronger winds will mix down to the surface by midday allowing gusts of 25 to 30 mph at times. Winds will remain 10 to 15 mph and gusty overnight tonight as another cold front brings a surge of arctic air to the area. A period with potential LLWS will occur during the later evening and early morning hours tonight in the wake of this front. This potential will be examined more closely for the 18Z TAF cycle. && .MARINE... Advisory level northerly winds are occurring across the forecast waters in the wake of a cold front. A stronger secondary cold front will cross the area this evening. High end advisory level winds and rough seas are expected overnight into Tuesday morning. Based on the expected the degree of cold air advection, and the latest low level BUFR profiles, wind gusts of 35 to 40 knots are becoming more likely. The best timing for gale force gusts will fall between late evening and sunrise. Winds and seas will then gradually diminish later Tuesday into Tuesday night as high pressure builds over the Northeast Gulf of Mexico. && .FIRE WEATHER... A cold front pushed across the Tri-State Area late Sunday, and colder and much drier air will be spreading across the area today and tonight, on the heels of strong gusty northwest winds. Critical values of relative humidity plus strong 20 foot winds will combine to produce Red Flag conditions across the entire Tri-State Area later today, and a Red Flag Warning has been issued for all of our Alabama, Georgia and Florida counties. On Tuesday, durations of low relative humidity will likely meet Red Flag criteria across our Florida counties, and there is a high probability that they will meet criteria across our Georgia counties as well. In southeast Alabama, durations will be marginal and the 20 foot winds are not expected to meet criteria. However, due to the uncertainty in the forecast, a Fire Weather Watch has been issued for all of our Florida, Georgia and Alabama counties for Tuesday, and conditions will need to be closely monitored. In addition, a secondary cold front will sweep across the area later this evening, and very cold arctic air will spread across the area tonight and Tuesday. Expect a long duration widespread freeze event tonight, and again on Tuesday night into Wednesday morning. Finally, with very dry air remaining in place across much of the area through Wednesday, conditions will need to be monitored for possible Red Flag warnings, mainly across our Florida counties again on Wednesday afternoon. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 57 27 43 18 52 / 0 0 0 0 0 Panama City 59 28 46 28 54 / 0 0 0 0 0 Dothan 56 27 42 24 53 / 0 0 0 0 0 Albany 56 26 42 22 52 / 0 0 0 0 0 Valdosta 56 26 42 21 52 / 0 0 0 0 0 Cross City 60 27 45 18 53 / 0 0 0 0 0 Apalachicola 60 34 46 26 53 / 0 0 0 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...Freeze Warning from Midnight tonight to 8 AM CST Tuesday for Coffee-Dale-Geneva-Henry-Houston. Fire Weather Watch from 11 AM CST this morning through this afternoon for Coffee-Dale-Geneva-Henry-Houston. Wind Advisory until Midnight CST tonight for Coffee-Dale-Geneva- Henry-Houston. GA...Freeze Warning from 1 AM to 9 AM EST Tuesday for Baker-Ben Hill- Berrien-Brooks-Calhoun-Clay-Colquitt-Cook-Decatur-Dougherty- Early-Grady-Irwin-Lanier-Lee-Lowndes-Miller-Mitchell- Quitman-Randolph-Seminole-Terrell-Thomas-Tift-Turner-Worth. Fire Weather Watch from Noon EST today through this afternoon for Baker-Ben Hill-Berrien-Brooks-Calhoun-Clay-Colquitt- Cook-Decatur-Dougherty-Early-Grady-Irwin-Lanier-Lee-Lowndes- Miller-Mitchell-Quitman-Randolph-Seminole-Terrell-Thomas- Tift-Turner-Worth. Wind Advisory until 1 AM EST Tuesday for Baker-Ben Hill-Berrien- Brooks-Calhoun-Clay-Colquitt-Cook-Decatur-Dougherty-Early- Grady-Irwin-Lanier-Lee-Lowndes-Miller-Mitchell-Quitman- Randolph-Seminole-Terrell-Thomas-Tift-Turner-Worth. FL...Freeze Warning from 1 AM EST /Midnight CST/ to 9 AM EST /8 AM CST/ Tuesday for Calhoun-Central Walton-Coastal Bay-Coastal Dixie-Coastal Franklin-Coastal Gulf-Coastal Jefferson- Coastal Taylor-Coastal Wakulla-Gadsden-Holmes-Inland Bay- Inland Dixie-Inland Franklin-Inland Gulf-Inland Jefferson- Inland Taylor-Inland Wakulla-Inland Walton-Jackson- Lafayette-Leon-Liberty-Madison-South Walton-Washington. Fire Weather Watch from Noon EST /11 AM CST/ today through this afternoon for Calhoun-Central Walton-Coastal Bay-Coastal Dixie-Coastal Franklin-Coastal Gulf-Coastal Jefferson- Coastal Taylor-Coastal Wakulla-Gadsden-Holmes-Inland Bay- Inland Dixie-Inland Franklin-Inland Gulf-Inland Jefferson- Inland Taylor-Inland Wakulla-Inland Walton-Jackson- Lafayette-Leon-Liberty-Madison-South Walton-Washington. Wind Advisory until 1 AM EST /Midnight CST/ Tuesday for Calhoun- Central Walton-Coastal Bay-Coastal Dixie-Coastal Franklin- Coastal Gulf-Coastal Jefferson-Coastal Taylor-Coastal Wakulla-Gadsden-Holmes-Inland Bay-Inland Dixie-Inland Franklin-Inland Gulf-Inland Jefferson-Inland Taylor-Inland Wakulla-Inland Walton-Jackson-Lafayette-Leon-Liberty- Madison-South Walton-Washington. GM...Gale Watch through Tuesday morning for Apalachee Bay-Coastal waters From Ochlockonee River to Apalachicola FL out to 20 NM-Coastal waters from Suwannee River to Keaton Beach FL out 20 NM-Coastal waters from Apalachicola to Destin FL out 20 NM-Waters from Suwannee River to Apalachicola FL from 20 to 60 NM-Waters from Apalachicola to Destin FL from 20 to 60 NM. && $$ MROCZKA/EVANS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
333 AM EST MON JAN 2 2012 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW && .SYNOPSIS... A STRONG LOW PRESSURE SYSTEM EXITING THE GREAT LAKES TONIGHT TO THE NORTHEAST AND STRONG CANADIAN HIGH PRESSURE BUILDING INTO THE PLAINS WILL KEEP GUSTY WINDS OVER THE AREA THROUGH MONDAY EVENING. NORTHERLY AND NORTHWESTERLY WINDS OFF LAKE MICHIGAN WILL KEEP LOW CHANCES FOR LAKE EFFECT SNOW SHOWERS OVER THE NORTHEAST COUNTIES MONDAY INTO TUESDAY. A BROAD RIDGE OF HIGH PRESSURE WILL THEN DOMINATE THE WEATHER THROUGH THE REMAINDER OF THE PERIOD AND KEEP DRY WEATHER IN PLACE. TEMPERATURES WILL DROP BELOW NORMAL FOR THE BEGINNING OF THE WORK WEEK BUT REBOUND TO NEAR NORMAL BY WEDNESDAY AND ABOVE NORMAL ON THURSDAY. && .NEAR TERM /REST OF TONIGHT/... WILL UPDATE SHORTLY TO END THE WIND ADVISORY AND ADD SLIGHT CHANCE SNOW SHOWERS TO MUCH OF THE AREA. UPSTREAM WIND GUSTS ARE GENERALLY BELOW CRITERIA AS EXPECTED...AND OURS HAVE BEEN SLOWLY RELAXING AS WELL. GUSTS TO 35-40 MPH WILL CONTINUE OVERNIGHT...REMAINING JUST BELOW CRITERIA AT THEIR PEAK. BROAD AREA OF LIGHT RADAR RETURNS OVER THE REGION...WITH SOME OF THEM OCCASIONALLY MAKING THE GROUND. WEBCAMS INDICATE A LIGHT DUSTING IN THE MUNCIE AREA. RUC SOUNDINGS SUGGEST SNOW GROWTH LAYER SLOWLY MOISTENING OVERNIGHT AS A SECONDARY SHORTWAVE SPINS AROUND THE BACK SIDE OF THE UPPER TROUGH. THUS...FEEL THAT AT LEAST A SLIGHT CHANCE OF SNOW SHOWERS IS NECESSARY. NO ACCUMULATIONS BEYOND A VERY LIGHT DUSTING POSSIBLE...AS DRY AIR NEAR THE SURFACE WILL BE SUBLIMATING MUCH OF THE SNOW AS IT FALLS. && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... FORECAST FOCUS IS ON WIND GUSTS MONDAY AND CHANCES FOR SNOW SHOWERS WITH LAKE EFFECT IN THE WAKE OF THE COLD FRONT. MODELS ARE IN GOOD AGREEMENT AND WILL USE A CONSENSUS APPROACH. A TIGHT PRESSURE GRADIENT WILL CONTINUE TO BE IN PLACE MONDAY AS INDIANA IS BETWEEN STRONG HIGH AND LOW PRESSURE SYSTEMS. THIS WILL ALLOW SUSTAINED WINDS AROUND 20-25 MPH AND GUSTS OF 30-40 MPH TO PERSIST THROUGH THE DAY UNTIL THE GRADIENT FINALLY BEGINS TO SLACKEN MONDAY NIGHT AS THE STRONG LOW FINALLY EXITS UP THE EASTERN CANADIAN SEABOARD AND HIGH PRESSURE MOVES CLOSER TO INDIANA. AT THIS TIME FORECAST SOUNDINGS ARE NOT SHOWING WINDS QUITE AS STRONG AS TODAY SO IT DOES NOT APPEAR THAT ANOTHER ADVISORY WILL BE NECESSARY. A WEAK IMPULSE WILL MOVE THROUGH THE AREA TOMORROW ON THE BACK SIDE OF THE LOW...AND THIS EXTRA BIT OF FORCING ALONG WITH 850 MB WINDS BECOMING NORTH NORTHWESTERLY COULD ALLOW A FEW SNOW SHOWERS TO FORM ACROSS NORTHEASTERN PARTS OF THE AREA MONDAY AFTERNOON. THESE WINDS WILL CONTINUE TO PROVIDE A GOOD FETCH ACROSS LAKE MICHIGAN TO PRODUCE THE POTENTIAL FOR SOME LAKE EFFECT SNOW STRETCHING INTO THE NORTHEASTERN COUNTIES THROUGH THE MORNING ON TUESDAY. AT THIS TIME IT DOES NOT LOOK LIKE AMOUNTS WILL BE SIGNIFICANT WITH LESS THAN AN INCH EXPECTED THROUGH TUESDAY. FLURRIES COULD EXTEND FURTHER TO THE WEST. BY TUESDAY AFTERNOON THE WIND DIRECTION BACKS TO MORE WESTERLY AND THIS WILL SHUT OFF ANY LAKE ACTIVITY. ANOTHER WEAK WAVE AND FRONT WILL MOVE THROUGH ON WEDNESDAY...BUT AT THIS TIME THE MOISTURE AND FORCING WITH THIS FEATURE STAY NORTH OF THE AREA AND THUS WILL KEEP THE FORECAST DRY. TEMPERATURES WILL BE COLDER THAN NORMAL EARLY IN THE SHORT TERM AND START TO REBOUND TO NORMAL ON WEDNESDAY. GENERALLY USED A CONSENSUS OF GUIDANCE BUT THOUGHT TUESDAY/S MAV HIGHS WERE TOO LOW BASED ON 850 MB TEMPERATURES AND LESS CLOUD COVER SO WENT WITH THE WARMER GUIDANCE THEN. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... OVERALL THE EXTENDED WILL BE RATHER QUIET WITH ABOVE NORMAL TEMPERATURES AS THE PATTERN TRANSITIONS FROM AN UPPER RIDGE OVER THE ROCKIES AND A UPPER TROUGH NEAR THE EAST COAST EARLY ON TO A MORE ZONAL FLOW FROM FRIDAY ON. HIGH PRESSURE MOVING EAST ACROSS THE SOUTHERN U.S. WILL DOMINATE OUR WEATHER THURSDAY AND FRIDAY. THEN MODELS BRING A VERY WEAK COLD FRONT ACROSS OUR REGION SATURDAY. MODELS HAVE TRENDED DRIER WITH THIS COLD FRONT AND NOW INDICATE PRECIP WILL PASS BOTH NORTH AND SOUTH OF OUR REGION AROUND SATURDAY BUT MISSING OUR REGION. WILL FOLLOW SUIT AND GO DRY THROUGH THE PERIOD. WILL MAKE SOME MINOR ADJUSTMENTS IN TEMPERATURES TO GO A LITTLE WARMER THAN ALL BLEND AROUND FRIDAY AS WARM ADVECTION WILL BE OCCURRING AHEAD OF THE COLD FRONT AND SOME OF THE GUIDANCE IS TRENDING EVEN WARMER. OTHERWISE...ALL BLEND TEMPERATURES LOOK REASONABLE MOST OTHER PERIODS. && .AVIATION /DISCUSSION FOR THE 02/09Z TAF UPDATE/... UPDATE... NO CHANGES. PREVIOUS DISCUSSION... A STRONG PRESSURE GRADIENT WILL DECREASE SLIGHTLY OVER CENTRAL INDIANA AS A SURFACE LOW OVER GREAT LAKES TRACKS TO THE NORTHEAST...AND FARTHER AWAY FROM THE REGION. WILL CONTINUE OVC CEILINGS AROUND 4K FT AND -SHSN. RESTRICTIONS TO VIS APPEAR TO BE AT A MINIMUN SO WILL MAINTAIN VFR. AS FAR AS WINDS ARE CONCERNED THEY CONTINUE TO DECREASE ONLY SLIGHTLY OVER THE NEXT FEW HOURS BUT WILL CONTINUE TO GUST EARLY THIS MORNING AND THROUGH TOMORROW...REACHING AROUND 25 TO 30 KNOTS. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...CP NEAR TERM...NIELD SHORT TERM...CP LONG TERM....JEH AVIATION...SMF/TDUD
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1240 AM EST MON JAN 2 2012 ...MAJOR WINTER STORM TO IMPACT REGION... .AVIATION... RADAR SHOWING POCKETS OF HEAVIER SNOW SHOWERS STILL STRUGGLING TO CONGEAL WITH 40 TO 50 KNOT 925 TO 850MB LAYER WINDS SHEARING APART DEVELOPMENT. EXPECT THESE WINDS TO DIMINISH SOMEWHAT OVERNIGHT ALLOWING BETTER BANDING TO DEVELOP WITH HEAVIER SNOWFALL RATES AND LOWER VISIBILITIES. PREVIOUS FORECAST ON TRACK WITH NO SIGNIFICANT CHANGES MADE. LOWER CIGS AND VIS EXPECTED IN STRONGER SNOW SHOWERS AND UPDATES LIKELY AS THESE DEVELOP AND EVOLVE. FLOW VEERS TO MORE NORTHWESTERLY DIRECTION MONDAY ALLOWING STRONGER BANDS TO IMPACT KSBN BEGINNING IN THE MORNING AND REACHING KFWA IN AFTERNOON. TRAJECTORIES SUGGEST KSBN TO REMAIN NEAR OR IN STRONGEST BAND THROUGH MONDAY NIGHT. KFWA WILL BE ON SOUTHEAST END OF BAND WITH MVFR CIGS AND VIS AND OCCASIONAL DROP TO IFR POSSIBLE. && .PREV FORECAST... WILL EXPAND CAT SNOW MENTION/MEASURABLE QPF FURTHER SWD THIS EVENING IN REFLECTION OF UPSTREAM ENHANCEMENT DVLPG THROUGH SE WI. WELL DEFINED SEEDER-FEEDER MECHANISM NOTED EXTENDING DOWNSTREAM IN COMPOSITE RADAR IMAGERY ACRS NRN IN/SRN MI AND BASED CAT EXPANSION ON STEADY STATE 290 DEGREE SFC TRAJECTORY. EARLIER HIGHRES MODEL DATA ALG W/LATEST RUC DATA WOULD SUGGEST ADDNL LL VEERING OVERNIGHT TWD 310-320 DEGREES AFT 06Z AND PROBABLE GIVEN VAPOR HINTS OF AN ADDNL SW IMPULSE DROPPING SEWD OUT OF NRN IA THUS EXPANDED CAT SNOW SHOWER MENTION FURTHER SWD HERE TOO AS WELL. SFC GRADIENT CONTS TO SLOWLY DIMINISH AND WILL ALLOW BOTH WIND ADVISORY AND STORM WARNING TO EXPIRE AT 03Z. AVIATION/UPDATE... SECONDARY SW TROUGH PIVOTING THROUGH NRN IN ATTM W/ROBUST SHSN DVLPMNT OVR THE LAST HOUR W/RAPIDLY DETERIORATING FLIGHT CONDS THIS EVENING. OTHERWISE GROWING LK RESPONSE GOING FORWARD AS CAA WING DEEPENS BEHIND DEPARTING SW TROUGH AND XPCD MORE COHERENT LK ENHANCEMENT AFT 03Z TIMED W/ARRIVAL OF MID LVL MSTR POCKET ADVTG SEWD OUT OF WI W/PRIOR UPDATE DONE TO ACCOUNT FOR THAT. THUS PRIMARILY MVFR CONDS XPCD THROUGH THE PD W/LIFR CONDS LIKELY MON AFTN AND MON NIGHT AT KSBN IN HEAVY LK EFFECT SNOW. GUSTY SFC WINDS WILL CONT THROUGH ABT MIDNIGHT BFR DIMINISHING SOMEWHAT FOR THE REMAINDER OF THE VALID PD. SHORT TERM... TONIGHT THROUGH TUESDAY. CONTD GROWING CONCERN AND CONFIDENCE IN MAJOR LES EVENT WITH BLSN ADDNL HAZARD. FAVOR LIES TOWARD NAM12/WRFARW FOR MESOSCALE DETAILING. WRFARW BEST HANDLES GRTLKS COMPLEX /TRIPLE SHORTWAVE EMBEDDED/ MIDLVL TROUGH UNDERGOING RAPIDLY DEEPENING IN NEAR TERM AS IT CONTS TO SHARPEN AND SLOWLY TRANSLATE EWD INTO LWR GRTLKS TONIGHT...AND THEN INTO NEW ENGLAND BY ERLY TUE TUE...WITH ASSOCD 200-250M/12 HR HGHT FALL CENTROID. GREATEST NEGATIVE IN NEAR TERM IS CBL FLOW INITIALLY QUITE STRONG /NEAR 40KTS/ WITH LYR TO LYR SHEAR NOTED TO UNDERMINE MESOSCALE PROCESSES AND CONSEQUENTIAL LESSER RESIDENCE TIME. INITIAL WEAKER MULTIBANDS ALREADY UNDERWAY WITH LK/8H DELTA TS INTO MID TEENS ALREADY. DEEPER/CONCENTRATED CONVECTIVE ROLLS TO LKLY BECOME ESTABLISHED AS IN CLOUD WINDS DIMINISH TO AROUND 35 KTS BY DAYBREAK...WITH MORE UNIFORM CBL VECTORING. PER KAZO/KSBN NAM BUFKIT...DEEP 70-90MB DGZ LYR TOWARD DAYBREAK WITH FAIR DEGREE OF SATURATION /85-90 PERCENT/ AS DEEPER COLD AIR BECOMES ESTABLISHED PUSHING DELTA T INTO UPPER TEENS WITH LK/7H DIFFERENTIALS INTO MID 20C RANGE. DEEP THERMAL INSTABILITY TO BE FULLY UTILIZED GIVEN MSTR DEPTH. GOOD SYNOPTIC MSTR/PRECONDITIONING WITH SFC DPS WELL WINDWARD OF LK MICHIGAN TO MID 20F FAR NWD TO MN BORDER. GRAVE CONCERN FOR XTRM SNOWFALL RATES DVLPG MON INTO TUE WITH 5H THERMAL TROF BOTTOMING OVHD TO M37-38...PERHAPS SUFCNT FOR LTG IN HVST SQUALLS ESPLY MONDAY AFTN WITH DEEP SATURATION TO 7H WITH LK/7H DIFFERENTIALS NEARING XTRM VALUES/30C AND LAKE INDUCED CAPE VALUES APPROACHING 600 J/KG WITH LK INDUCED EQL TO 11.5 KFT. PLANAR VIEW DEPICTING BEST ORGANIZED CONVERGENCE INITIALLY FM KLWA INTO BRANCH COUNTY SLIPPING SWD AS WINDS GRDLY VEER FM 305 TO 335 THROUGH THE DAY. MAXIMUM SNOWFALL RATES GIVEN XTRM INSTABILITY TO 2 INCHES/HR ANTICIPATED UNDER WHAT SHOULD DVLP INTO PRIMARY SINGLE BAND EVENT...OR AT LEAST FEWER STRONGER BANDS WITH SRN BAND BECMG UNDER INFLUENCE OF WRN LK SUPR PRECONDITIONING BY AFTN. DY2 CONVECTION NOTED AND CERTAINLY PSBL...WL HOLD ON THUNDERSNOW MENTION ATTM GIVEN AREA/TIMING CONCERNS ATTM FOR LOW PROB EVENT...BUT CERTAINLY OCCRNC TO PUSH RATES MORE TOWARD 3/HR. FOR NOW HAVE EXPANDED HEADLINES FURTHER INLAND AND WHILE LES AMOUNTS FURTHER INLAND SIG LWR...MULTIHAZARDS JUSTIFY UPG/EXPANDED AREA WITH BLSN LEADING TO FLASH FREEZING/RECOVERING OF ROAD SURFACES/LOW VSBY/WCI DROPPING TO NEAR ZERO ETC. HAVE RAISED POPS/AMOUNTS IN WARNING AND PERIPHERAL ADV AREAS...ESP NRN KOS/NRN MARSHALL COUNTIES AND FURTHER INLAND INTO SCNTL LWR MICHIGAN WITH HIR CONFIDENCE OF AFOREMENTIONED DOMINANT BAND REACHING/CYLONICALLY CURVING WELL INLAND LTR TONIGHT/MON AM. CONFIDENCE IN HIR WARNING AMOUNTS NRN BERRIEN/WRN CASS COUNTIES PER CONTD IMPRESSIVE COBB NAM OUTPUT AT KSBN/KAZO. OF CONCERN IS SHARP SFC/LLVL RIDGE STAGED STILL WEST OF CWA TUE AM THAT A FULL AXIS LES BAND TO DVLP AND PERSIST WELL INTO TUESDAY...PRIMARILY AFFECTING BERRIEN/LAPORTE AS FETCH CONTS TO VEER ES TO 340 DEGREES AND CBL SLOWS TO LWR 20 KNOTS. WHILE MSTR DEPTH SIG LESS...CONCERNED THAT MESOSCALE MODELS STILL UNDERPLAYING COMBINED LK/SUPR/MI AGGREGATE THERMAL TROUGHING FURTHER OUT IN TIME AND THEREBY NOT CAPTURING FULL POTNL WITH STRONG MSTR FLUX/CONVERGENCE TO LKLY PERSIST. HAVE RAISED POPS FAR NWRN CWA FOR FIRST HALF OF TUE AND NOTE POTNL EXTENSION FOR BERRIEN AND LAPORTE COUNTIES MAY BE NEEDED...BUT CERTAINLY ENOUGH TIME TO ASSESS LTR. LONG TERM... TUESDAY NIGHT THROUGH SATURDAY....THE 850 RIDGE AXIS SHOULD HAVE MOVED JUST EAST OF LAKE MICHIGAN AT THE START OF THIS PERIOD...SO HAVE KEPT LAKE EFFECT SNOW OUT OF THE FORECAST TUESDAY NIGHT. WARM AIR ADVECTION WILL BE INCREASING TUESDAY NIGHT AHEAD OF THE NEXT SYSTEM...SO LOWS TUESDAY NIGHT SHOULD ONLY DROP A FEW DEGREES FROM THE TUESDAY HIGHS. HOWEVER..A CLIPPER TYPE OF SYSTEM WILL PASS NORTH OF THE AREA WEDNESDAY. KEPT A CHANCE FOR SNOW BASICALLY OVER THE NORTHEAST HALF OF THE FORECAST AREA. ISENTROPIC LIFT IS SUFFICIENT...BUT MOISTURE SOUTH OF THIS SYSTEM IS QUITE LIMITED...SO EXPECT ANY SNOW AMOUNTS LATE TUESDAY NIGHT AND WEDNESDAY WILL BE LIGHT. OTHERWISE...AN UPPER LEVEL RIDGE WILL ATTEMPT TO BUILD INTO THE REGION LATE IN THE WEEK. TEMPERATURES SHOULD WARM MUCH ABOVE NORMAL BY FRIDAY...WITH HIGHS IN THE LOW TO MID 40S. KEPT A SLIGHT CHANCE FOR A RAIN OR SNOW SHOWER SATURDAY AS A WEAK TROF MOVES INTO THE FORECAST AREA. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...WIND ADVISORY UNTIL 10 PM EST /9 PM CST/ THIS EVENING FOR INZ003>009-012>018-020-022>027-032>034. WINTER STORM WARNING UNTIL 7 AM EST TUESDAY FOR INZ005-006. WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR INZ007>009. WINTER STORM WARNING FROM 4 AM EST /3 AM CST/ MONDAY TO 7 AM EST /6 AM CST/ TUESDAY FOR INZ003-004. WINTER WEATHER ADVISORY FROM 4 AM EST /3 AM CST/ MONDAY TO 7 AM EST /6 AM CST/ TUESDAY FOR INZ012-014-016. MI...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR MIZ078>081. WINTER STORM WARNING UNTIL 7 AM EST TUESDAY FOR MIZ077>080. WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR MIZ081. HIGH WIND WARNING UNTIL 7 PM EST THIS EVENING FOR MIZ077. OH...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR OHZ001-002-004- 005-015-016-024-025. WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR OHZ001. LM...STORM WARNING UNTIL 10 PM EST THIS EVENING FOR LMZ043-046. GALE WARNING FROM 10 PM THIS EVENING TO 11 PM EST MONDAY FOR LMZ043-046. && $$ SHORT TERM...MURPHY LONG TERM...SKIPPER AVIATION...LASHLEY UPDATE...T
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1128 PM EST SUN JAN 1 2012 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... A STRONG LOW PRESSURE SYSTEM EXITING THE GREAT LAKES TONIGHT TO THE NORTHEAST AND STRONG CANADIAN HIGH PRESSURE BUILDING INTO THE PLAINS WILL KEEP GUSTY WINDS OVER THE AREA THROUGH MONDAY EVENING. NORTHERLY AND NORTHWESTERLY WINDS OFF LAKE MICHIGAN WILL KEEP LOW CHANCES FOR LAKE EFFECT SNOW SHOWERS OVER THE NORTHEAST COUNTIES MONDAY INTO TUESDAY. A BROAD RIDGE OF HIGH PRESSURE WILL THEN DOMINATE THE WEATHER THROUGH THE REMAINDER OF THE PERIOD AND KEEP DRY WEATHER IN PLACE. TEMPERATURES WILL DROP BELOW NORMAL FOR THE BEGINNING OF THE WORK WEEK BUT REBOUND TO NEAR NORMAL BY WEDNESDAY AND ABOVE NORMAL ON THURSDAY. && .NEAR TERM /REST OF TONIGHT/... WILL UPDATE SHORTLY TO END THE WIND ADVISORY AND ADD SLIGHT CHANCE SNOW SHOWERS TO MUCH OF THE AREA. UPSTREAM WIND GUSTS ARE GENERALLY BELOW CRITERIA AS EXPECTED...AND OURS HAVE BEEN SLOWLY RELAXING AS WELL. GUSTS TO 35-40 MPH WILL CONTINUE OVERNIGHT...REMAINING JUST BELOW CRITERIA AT THEIR PEAK. BROAD AREA OF LIGHT RADAR RETURNS OVER THE REGION...WITH SOME OF THEM OCCASIONALLY MAKING THE GROUND. WEBCAMS INDICATE A LIGHT DUSTING IN THE MUNCIE AREA. RUC SOUNDINGS SUGGEST SNOW GROWTH LAYER SLOWLY MOISTENING OVERNIGHT AS A SECONDARY SHORTWAVE SPINS AROUND THE BACK SIDE OF THE UPPER TROUGH. THUS...FEEL THAT AT LEAST A SLIGHT CHANCE OF SNOW SHOWERS IS NECESSARY. NO ACCUMULATIONS BEYOND A VERY LIGHT DUSTING POSSIBLE...AS DRY AIR NEAR THE SURFACE WILL BE SUBLIMATING MUCH OF THE SNOW AS IT FALLS. && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... FORECAST FOCUS IS ON WIND GUSTS MONDAY AND CHANCES FOR SNOW SHOWERS WITH LAKE EFFECT IN THE WAKE OF THE COLD FRONT. MODELS ARE IN GOOD AGREEMENT AND WILL USE A CONSENSUS APPROACH. A TIGHT PRESSURE GRADIENT WILL CONTINUE TO BE IN PLACE MONDAY AS INDIANA IS BETWEEN STRONG HIGH AND LOW PRESSURE SYSTEMS. THIS WILL ALLOW SUSTAINED WINDS AROUND 20-25 MPH AND GUSTS OF 30-40 MPH TO PERSIST THROUGH THE DAY UNTIL THE GRADIENT FINALLY BEGINS TO SLACKEN MONDAY NIGHT AS THE STRONG LOW FINALLY EXITS UP THE EASTERN CANADIAN SEABOARD AND HIGH PRESSURE MOVES CLOSER TO INDIANA. AT THIS TIME FORECAST SOUNDINGS ARE NOT SHOWING WINDS QUITE AS STRONG AS TODAY SO IT DOES NOT APPEAR THAT ANOTHER ADVISORY WILL BE NECESSARY. A WEAK IMPULSE WILL MOVE THROUGH THE AREA TOMORROW ON THE BACK SIDE OF THE LOW...AND THIS EXTRA BIT OF FORCING ALONG WITH 850 MB WINDS BECOMING NORTH NORTHWESTERLY COULD ALLOW A FEW SNOW SHOWERS TO FORM ACROSS NORTHEASTERN PARTS OF THE AREA MONDAY AFTERNOON. THESE WINDS WILL CONTINUE TO PROVIDE A GOOD FETCH ACROSS LAKE MICHIGAN TO PRODUCE THE POTENTIAL FOR SOME LAKE EFFECT SNOW STRETCHING INTO THE NORTHEASTERN COUNTIES THROUGH THE MORNING ON TUESDAY. AT THIS TIME IT DOES NOT LOOK LIKE AMOUNTS WILL BE SIGNIFICANT WITH LESS THAN AN INCH EXPECTED THROUGH TUESDAY. FLURRIES COULD EXTEND FURTHER TO THE WEST. BY TUESDAY AFTERNOON THE WIND DIRECTION BACKS TO MORE WESTERLY AND THIS WILL SHUT OFF ANY LAKE ACTIVITY. ANOTHER WEAK WAVE AND FRONT WILL MOVE THROUGH ON WEDNESDAY...BUT AT THIS TIME THE MOISTURE AND FORCING WITH THIS FEATURE STAY NORTH OF THE AREA AND THUS WILL KEEP THE FORECAST DRY. TEMPERATURES WILL BE COLDER THAN NORMAL EARLY IN THE SHORT TERM AND START TO REBOUND TO NORMAL ON WEDNESDAY. GENERALLY USED A CONSENSUS OF GUIDANCE BUT THOUGHT TUESDAY/S MAV HIGHS WERE TOO LOW BASED ON 850 MB TEMPERATURES AND LESS CLOUD COVER SO WENT WITH THE WARMER GUIDANCE THEN. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... OVERALL THE EXTENDED WILL BE RATHER QUIET WITH ABOVE NORMAL TEMPERATURES AS THE PATTERN TRANSITIONS FROM AN UPPER RIDGE OVER THE ROCKIES AND A UPPER TROUGH NEAR THE EAST COAST EARLY ON TO A MORE ZONAL FLOW FROM FRIDAY ON. HIGH PRESSURE MOVING EAST ACROSS THE SOUTHERN U.S. WILL DOMINATE OUR WEATHER THURSDAY AND FRIDAY. THEN MODELS BRING A VERY WEAK COLD FRONT ACROSS OUR REGION SATURDAY. MODELS HAVE TRENDED DRIER WITH THIS COLD FRONT AND NOW INDICATE PRECIP WILL PASS BOTH NORTH AND SOUTH OF OUR REGION AROUND SATURDAY BUT MISSING OUR REGION. WILL FOLLOW SUIT AND GO DRY THROUGH THE PERIOD. WILL MAKE SOME MINOR ADJUSTMENTS IN TEMPERATURES TO GO A LITTLE WARMER THAN ALL BLEND AROUND FRIDAY AS WARM ADVECTION WILL BE OCCURRING AHEAD OF THE COLD FRONT AND SOME OF THE GUIDANCE IS TRENDING EVEN WARMER. OTHERWISE...ALL BLEND TEMPERATURES LOOK REASONABLE MOST OTHER PERIODS. && .AVIATION /DISCUSSION FOR 020600Z IND TAF ISSUANCE/... A STRONG PRESSURE GRADIENT WILL DECREASE SLIGHTLY OVER CENTRAL INDIANA AS A SURFACE LOW OVER GREAT LAKES TRACKS TO THE NORTHEAST...AND FARTHER AWAY FROM THE REGION. WILL CONTINUE OVC CEILINGS AROUND 4K FT AND -SHSN. RESTRICTIONS TO VIS APPEAR TO BE AT A MINIMUN SO WILL MAINTAIN VFR. AS FAR AS WINDS ARE CONCERNED THEY CONTINUE TO DECREASE ONLY SLIGHTLY OVER THE NEXT FEW HOURS BUT WILL CONTINUE TO GUST EARLY THIS MORNING AND THROUGH TOMORROW...REACHING AROUND 25 TO 30 KNOTS. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CP NEAR TERM...NIELD SHORT TERM...CP LONG TERM....JEH AVIATION...SMF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
651 PM EST TUE JAN 3 2012 UPDATED FOR 00Z AVIATION DISCUSSION .SHORT TERM /TONIGHT AND WED/... WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW THE NEXT SHORTWAVE TROF OF INTEREST HEADING SE THRU MANITOBA AND THE DAKOTAS. IMPRESSIVE WARMING IS NOTED AHEAD OF FEATURE. 850MB TEMPS AT KBIS/KABR/KINL HAVE JUMPED FROM -1/-6/-15C RESPECTIVELY AT 00Z TUE TO 11/9/-9C AT 12Z. STRONG WAA HAS YET TO YIELD ANY PCPN. ONLY SOME MID AND HIGH CLOUDS ARE NOTED. AS SHORTWAVE CONTINUES ESE...DON`T ANTICIPATE ANY PCPN TO DEVELOP IN ONGOING STRONG WAA GIVEN OVERALL RELATIVELY DRY ENVIRONMENT SHOWN ON THIS MORNINGS REGIONAL SOUNDINGS. THERE IS JUST ENOUGH LINGERING OVERWATER INSTABILITY TO GENERATE SOME -SHSN OFF THE LAKES UNDER SYNOPTIC FORCING. WIND SHOULD HAVE ENOUGH SOUTHERLY COMPONENT TO WARRANT A MENTION OF -SHSN OVER THE E THIS EVENING... AND ALSO OVER THE KEWEENAW LATER THIS EVENING AND OVER THE NE FCST AREA WED MORNING AS SW WINDS VEER WNW. OTHERWISE...CONCERN AFTER FROPA IS POTENTIAL FOR -FZDZ AS MIDLEVELS SHARPLY DRY WHILE MODELS INSIST THAT A SHALLOW MOIST LAYER (2-3KFT THICK) MATERIALIZES. TEMPS WITHIN THE SHALLOW MOIST LAYER ARE WARMER THAN -10C...SUGGESTING NO ICE NUCLEATION. SATELLITE/UPSTREAM OBS HAVE YET TO SHOW ANY LOW CLOUD DEVELOPMENT. HOWEVER...NOSE OF HIGHER SFC DWPTS WELL INTO THE 20S INTO SRN MANITOBA/ERN ND IS SUPPORTIVE OF A POTENTIAL LOW-CLOUD DECK DEVELOPING AS THE MOISTURE ADVECTS INTO COLDER AIRMASS OVER THE AREA TONIGHT. HAVE THUS INCLUDED A MENTION OF -FZDZ IN THE WNW WIND UPSLOPE AREAS OVER WRN UPPER MI LATE EVENING INTO THE MORNING HRS AND OVER THE NE FCST AREA WED. CONFIDENCE IS LOW. CLOSELY FOLLOWED REGIONAL GEM FOR TEMP TRENDS TONIGHT. SOME AREAS... ESPECIALLY W AND N...WILL SEE MINS EARLY THIS EVENING WITH TEMPS SLOWLY RISING THRU THE NIGHT. MAX TEMPS IN THE UPPER 20S AROUND 30F SHOULD BE THE RULE WED. .LONG TERM /WED NIGHT THROUGH NEXT TUESDAY/... WEAK SHORTWAVE WILL BE SLIDING THROUGH THE NW FLOW AT THE START OF THE PERIOD AND WILL LEAD TO SOME MID CLOUDS OVER MUCH OF THE CWA. LARGE DIFFERENCES IN H850 TEMPS BETWEEN 12Z NAM AND 06Z GFS...WITH THE NAM AROUND -6C AND GFS AROUND -9C OVER THE ERN LK. 12Z GEM AND 00Z ECMWF ARE A LITTLE CLOSER TO THE GFS THAN THE NAM. THESE DIFFERENCES PRODUCE UNCERTAINTY IN LK EFFECT CHANCES AND WILL JUST MENTION FLURRIES OVER THE NW WIND FAVORED AREAS E OF MUNISING WED NIGHT. AS SHORT TERM DISCUSSION MENTIONED...THERE COULD BE SOME DRIZZLE INSTEAD...BUT FELT CHANCES WERE TOO LIMITED TO MENTION. FLATTENING UPPER RIDGE ON THURS WILL BACK H850-500 WINDS TO THE WEST AND PRODUCE BROAD WAA OVER THE UPPER GREAT LKS. WITH MOISTURE STREAMING THROUGH THE UPPER FLOW...THINK THERE WILL BE SOME MID CLOUDS OVER THE AREA THURS INTO THURS NIGHT...BUT DRIER LLVLS WILL LIMIT PCPN EVEN WITH THE INCREASING WAA. SFC LOW DEVELOPING OVER THE CANADIAN ROCKIES ON THURS IN RESPONSE TO SHORTWAVE MOVING THROUGH THE NRN STREAM WILL SHIFT SE TOWARDS LK WINNIPEG BY 00Z FRI. DEEPEST MOISTURE AND STRONGEST WAA WILL OCCUR OVER SRN ONTARIO AND NRN LK SUPERIOR ALONG THE DEVELOPING WARM FRONT THURS AFTN INTO THE EVENING...SO WILL CONTINUE CHANCE PCPN MENTIONS THERE. WITH THE SFC LOW SLIDING THROUGH SRN ONTARIO THURS NIGHT AND FRI...SW HALF OF THE AREA WILL BE UNDER DRY WARM MID LVL AIR /H850 TEMPS RISING TOWARDS 2-3C BY 12Z FRI/. MODELS CONTINUE TO SHOW MOISTURE TRAPPED BELOW THE H900 INVERSION ON THURS NIGHT INTO THE FIRST PART OF FRI...WHICH COULD LEAD TO BROAD LOWER STRATUS AT LEAST ON THURS NIGHT. NOT ENTIRELY CONF ON AMNT/COVERAGE OF LOW CLOUDS...SO WILL CONTINUE PARTLY CLOUDY SKIES OVER THE SW HALF OF THE AREA. INCREASING WINDS...DRIER AIR...AND WEAKENING INVERSION ON FRI SHOULD DIMINISH CLOUD COVERAGE OVER THE SW HALF. THE REST OF THE AREA WILL BE ON THE EDGE OF THE MID CLOUDS FROM THE SYSTEM OVER THE N. WITH AREA IN WARM SECTOR...EXPECT ABOVE NORMAL TEMPERATURES ACROSS THE AREA ON FRI. WILL CONTINUE UPPER 30S FCST...BUT COULD SEE SOME LOWER 40S OVER THE SCNTRL...WHERE THE WARMEST LLVL AIR WILL BE LOCATED. DAYS 4 THROUGH 7 /FRI NIGHT THROUGH NEXT TUESDAY/... THE SFC LOW SHIFTING E THROUGH SERN ONTARIO AT THE START OF THE EXTENDED PERIOD...DROPPING A COLD FRONT WILL SE ACROSS THE CWA FRI NIGHT INTO SAT. DEEP MOISTURE/FORCING CONTINUE TO APPEAR LIMITED AND WILL CONTINUE ONLY LOW END CHANCE POPS WITH THE PASSAGE OF THE FRONT. THE COLD FRONT THAT DROPS ACROSS THE AREA LOOKS TO GET HUNG UP OVER UPPER MI AND NRN WI ON SAT NIGHT DUE TO LIMITED COLD AIR BEHIND TO GIVE IT A PUSH. ADDITIONAL LLVL MOISTURE FROM THE UPPER TROUGH ROTATING THROUGH AND H850 TEMPS GRADUALLY FALLING TOWARDS -14C BY SUN MORNING SHOULD LEAD TO A SLOWLY EXPANDING AREA OF LIGHT LES SAT NIGHT INTO SUN...MAINLY FOR NW WIND LOCATIONS. LACK OF COLD AIR GETTING FORCING INTO THE DGZ IS THE MAIN LIMITING FACTOR...SINCE INVERSION HEIGHTS WILL INITIALLY BE AROUND 6KFT AND PLENTY OF LLVL MOISTURE. DID BUMP POPS UP SOME FOR FAVORED LOCATIONS...BUT KEPT THEM IN THE LOW CHANCE CAT DUE TO LIMITED ACCUM POTENTIAL. HIGH PRESSURE WILL BUILD INTO LK SUPERIOR ON SUN AS UPPER TROUGH SHIFTS E. DRIER AIR AND SUBSIDENCE WILL LEAD TO LOWERING INVERSION HEIGHTS AND SHOULD TAPER OFF LES IN THE EVENING. UPPER GREAT LKS REGION SHIFTS BACK SLIGHTLY NW FLOW ALOFT AS THE RIDGE OVER THE WRN CONUS FLATTENS. THIS WILL ALLOW WARMER H850 TEMPS TO INVADE THE UPPER GREAT LKS REGION AND KEEP THE NRN STREAM WAVES RUNNING ALONG AND JUST N OF THE U.S./CANADIAN BORDER. EXTENDED MODELS CONTINUING TO SHOW WAVE AFFECTING SRN ONTARIO ON MON...WHICH MAY PUSH SOME PCPN OVER THE NE HALF OF THE CWA...OTHERWISE THE FAIRLY QUIET AND ABOVE NORMAL TEMP PATTERN OF WINTER CONTINUES. && .AVIATION /FOR THE 00Z TAF ISSUANCE/... VFR CONDITIONS SHOULD PREVAIL THROUGH THE EVENING HRS AT KIWD/KCMX/KSAW UNDER A RELATIVELY DRY AIRMASS. WITH SFC HIGH PRES EXITING TO THE E...A STRENGTHENING S WIND DEVELOPED THIS AFTERNOON BTWN THE DEPARTING HI AND A DISTURBANCE/AREA OF PRES FALLS PASSING THRU NRN ONTARIO. S WINDS MAY STILL GUST AOA 20 KT INTO EARLY EVENING AT KIWD AND KSAW...BUT OTHERWISE EXPECT WINDS TO DECOUPLE WITH THE POSSIBILITY OF LLWS DEVELOPING. AS THE ONTARIO DISTURBANCE MOVES FARTHER TO THE E TONIGHT...A LOW PRES TROF WILL SWING ACROSS UPPER MI. AS THE FLOW VEERS TO THE WNW...EXPECT LOW CLDS/MVFR CIGS AND PERHAPS SOME -FZDZ OR -SN TO DEVELOP WHERE THIS FLOW UPSLOPES AT KCMX/KIWD. CONFIDENCE IS LOW. DOWNSLOPE NATURE OF THE WIND AT KSAW WILL LIMIT THIS POTENTIAL THERE. EXPECT MVFR CIGS TO LIFT BTWN 16-18Z ON WED AT ALL SITES WITH VFR CONDITIONS FOR THE REST OF WED AFTERNOON. && .MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/... PERIOD OF S TO SW GALES ARE EXPECTED LATE AFTN/EVENING OVER MUCH OF LAKE SUPERIOR AS PRES GRADIENT TIGHTENS BTWN DEPARTING HIGH PRES AND APPROACHING LOW PRES TROF. HEALTHY AREA OF PRES FALLS (CURRENTLY 8MB/3HR JUST NW OF LAKE SUPERIOR) SHOULD BE SUFFICIENT TO NUDGE WINDS TO GALE FORCE AS PRES FALLS SHIFT EASTWARD THIS EVENING. SW WIND WILL VEER TO THE NW LATER TONIGHT WED...WITH SPEEDS UP TO 25-30 KTS. AS AN AREA OF HIGH PRES MOVES INTO ONTARIO THU...WINDS OVER THE LAKE WILL DIMINISH BLO 20KT. LOOK FOR A STRONGER WESTERLY WIND OF 25-30 KTS TO RETURN FRI FOLLOWING THE PASSAGE OF ANOTHER LOW PRES SYSTEM THRU ONTARIO. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ266-267. GALE WARNING UNTIL 10 PM EST /9 PM CST/ THIS EVENING FOR LSZ162- 263-264. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...SRF AVIATION...VOSS MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1214 PM EST MON JAN 2 2012 .SYNOPSIS... ARCTIC HIGH PRESSURE WILL BRING COLD AND DRY CONDITIONS THROUGH MID WEEK WITH BRISK NORTHWEST WINDS. THE COLDEST TEMPERATURES SINCE LAST WINTER ARE EXPECTED TUESDAY NIGHT WITH LOWS IN THE TEENS OR LOWER 20S EXPECTED. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH WEDNESDAY...MODERATING LATE IN THE WEEK AND THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1230 PM MONDAY...TEMPERATURES ARE RISING SLOWLY AND THE TEMPERATURE CURVE IS LEVELING OFF AS MIXING BECOMES INCREASINGLY DEEP WITH THE COLD ADVECTION ALOFT. TEMPERATURES IN THE 49-52 RANGE WILL PROBABLY ONLY RISE ANOTHER 1-3 DEGREES THE REMAINDER OF THE DAY BEFORE PLUMMETING THIS EVENING. THIS IS ALL AS EXPECTED AND NO SIGNIFICANT CHANGES HAVE BEEN MADE WITH THIS EARLY AFTERNOON NEAR-TERM UPDATE. PREVIOUS DISCUSSION FROM 930 AM FOLLOWS... THE FIRST COLD FRONT IS NOW WELL OFFSHORE AND COOLER NORTHWEST WINDS COVER THE CAROLINAS. THE STRONG NORTHWEST FLOW ACROSS THE MOUNTAINS HAS SET UP A LEE-SIDE TROUGH EXTENDING FROM ROANOKE TO HICKORY TO GREENVILLE SC...AND IN RESPONSE A MESOSCALE RIDGE HAS POKED UP THROUGH THE SC/NC PIEDMONT REGION. THIS EFFECT APPEARS TO BE WELL-MODELED IN THE LATEST RUC MODEL WHICH SHOWS LIGHTER WINDS THAN INITIALLY EXPECTED ACROSS THE EASTERN CAROLINAS THIS AFTERNOON. MORE IMPORTANTLY TO OUR FORECAST...THE 12Z BALLOON SOUNDINGS FROM MOREHEAD CITY...CHARLESTON SC...AND GREENSBORO SHOWED THE LOWER ATMOSPHERE UP TO THE 850 MB LAYER AVERAGED 2 DEGREES FAHRENHEIT WARMER THAN ANY MODEL HAD FORECAST THIS MORNING. WE HAVE RAISED HIGHS NOT-COINCIDENTALLY BY 2 DEGREES ACROSS THE BOARD TODAY...WITH MID 50S NOW EXPECTED FOR MOST AREAS. NO CHANGES ARE EXPECTED FOR TONIGHT. AS STRONG UPPER LEVEL TROUGH WILL PUSH OFF THE COAST OVERNIGHT WITH TREMENDOUS COLD ADVECTION DEVELOPING. 850 MB TEMPERATURES WILL FALL FROM AROUND -5C TO -6C THIS EVENING TO A BONE-CHILLING -13C BY DAYBREAK TUESDAY. A DEEPLY-MIXED BOUNDARY LAYER WILL BE TOPPED OFF BY SOME HIGH STRATOCUMULUS/LOW ALTOCUMULUS CLOUDS TONIGHT WHICH HAPPEN TO FORM RIGHT WITHIN THE -12C TO -18C TEMPERATURES FOR EFFICIENT DENDRITIC SNOW CRYSTAL GROWTH. A DEEP AND VERY DRY SUBCLOUD LAYER SHOULD BE ENOUGH TO PREVENT ANY SNOW FLURRIES FROM REACHING THE GROUND OVER OUR PORTION OF THE CAROLINAS...BUT WE WILL LOOK AGAIN AT THE 12Z GUIDANCE FOR ANY DISCERNIBLE TRENDS IN BOUNDARY LAYER MOISTURE CONTENT TONIGHT. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 AM MONDAY...RAW AND BITTERLY COLD TUESDAY WITH HIGHS IN THE 30S AND WIND CHILLS STUCK IN THE 20S ALL DAY FOR MOST OF THE REGION. THE REGION WILL BE IN THE THROES OF ARCTIC AIR THROUGH THE PERIOD...BUT TUESDAY AND TUESDAY NIGHT WILL BRING THE COLDEST OF THE COLD. FIERCE COLD ADVECTION SHUTS OFF EARLY TUESDAY WITH THE PASSING OF THE LOW LEVEL THERMAL TROUGH. SAID TROUGH WILL HAVE 850MB TEMPS BOTTOMED OUT AT AN IMPRESSIVE -13C OR ABOUT 9F. THIS IS COLD ENOUGH THAT DESPITE A GOOD 6-7KFT OF MIXING HIGH TEMPERATURES WILL STAY IN THE 30S. GUSTY NW WINDS COULD EASILY REACH 30 MPH AT TIMES KEEPING THE WIND CHILL NOT ONLY BELOW FREEZING BUT POSSIBLY IN THE 20S ALL AFTERNOON. SINGLE DIGIT DEWPOINTS PAIRED WITH THE WIND WILL MAKE FOR SOME FIRE WX CONCERNS AS WELL. TUESDAY NIGHT WILL BE THE COLDEST PERIOD OF THE ARCTIC INVASION...BUT THERE IS SOME UNCERTAINTY ABOUT HOW IDEALIZED OF A RADIATIONAL COOLING SETUP IS IN PLACE. GUIDANCE SUGGESTING THAT THE HIGH MAY BE SUPPRESSED WELL ENOUGH TO THE SOUTH TO KEEP A FEW MPH OF WIND ALL NIGHT. INDEED FCST SOUNDINGS DO NOT SHOW THE VERY STEEP SFC BASED INVERSION TYPICAL OF AN ARCTIC RAD COOLING NIGHT. WITH THE HIGH OFF TO THE SOUTH THERE IS A SMALL SOUTHERLY COMPONENT TO THE SURFACE FLOW BY WED. MIXING WILL BE MORE SHALLOW AS COMPARED TO TUESDAY SO ANY WARMUP WILL BE QUITE GRADUAL. WEDNESDAY HIGHS IN THE UPPER 40S. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 3 AM MONDAY...SHARP UPPER TROUGH OVER THE NORTHEASTERN U.S. WILL BE LIFTING OUT ON THU ALLOWING FOR WEAK HEIGHT RISES OVER MUCH OF THE EAST WHILE WEAK SFC RIDGE BUILDS IN. THE HIGH PROGRESSES EAST AND END SUP OFF THE COAST BY FRIDAY NIGHT ALLOWING A RETURN OF ABOVE CLIMO TEMPS AND SOME MOISTURE ADVECTION. A VERY WEAK SOUTHERN BRANCH FEATURE NOW STAYS FAR ENOUGH TO OUR SOUTH OVER THE WEEKEND TO BE OF ANY CONSEQUENCE. A COLD FRONT MAY ENTER AND STALL ACROSS THE AREA ON SUNDAY...BEING LARGELY LINED UP WITH THE WSW FLOW ALOFT. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 18Z...VISIBLE SATELLITE LOOPS INDICATE CLEAR SKIES THIS AFTERNOON ACROSS THE TERMINALS. WITH A VERY DRY AIRMASS IN PLACE THERE IS HIGH CONFIDENCE OF VFR/CLEAR SKIES THROUGH THE AFTERNOON. WEST-NORTHWEST TO NORTHWEST WINDS WILL BECOME PROGRESSIVELY MORE WESTERLY BY LATE AFTERNOON AS SPEEDS DECREASE TO 5-7 KNOTS. A COLD FRONT WILL MOVE NORTHWEST TO SOUTHEAST ACROSS THE TERMINALS THIS EVENING. STRONG LIFT IS INDICATED WITH THE FRONT BUT MOISTURE IS LIMITED. DO NOT EXPECT ANY SIGNIFICANT PRECIPITATION...BUT THERE SHOULD BE A SHORT PERIOD OF CEILINGS AROUND 6K. THE CHANCE OF ANY SUB VFR CONDITIONS IS REMOTE ATTM. WINDS WILL SHIFT BACK TO THE NORTHWEST WITH FROPA AS SKIES CLEAR. AFTER SUNRISE STRONG COLD AIR ADVECTION AND A TIGHT PRESSURE GRADIENT WILL PRODUCE NORTHWEST WINDS WITH GUSTS TO 25-30 KNOTS UNDER VFR/CLEAR SKIES. NOTE...DUE TO AN ASOS OUTAGE THE KLBT TAF WILL INDICATE AMD NOT SKED UNTIL OBSERVATIONS ARE AGAIN AVAILABLE ON TUESDAY. EXTENDED OUTLOOK...VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1230 PM MONDAY...WINDS AND SEAS ARE BEHAVING AS EXPECTED. NO CHANGES WITH THIS NEAR-TERM EARLY AFTERNOON UPDATE. PREVIOUS DISCUSSION FROM 930 AM FOLLOWS... THE COLD FRONT IS WELL OFFSHORE AND COOL NORTHWEST WINDS ARE IN PLACE ACROSS THE COASTAL WATERS. THE COLD FRONT OFFSHORE IS A PRESSURE TROUGH ITSELF...AND THERE IS A LEE-SIDE TROUGH OF LOW PRESSURE IN THE NC/SC FOOTHILLS AS WELL. BETWEEN THESE TWO SYSTEMS A SMALL-SCALE RIDGE OF RELATIVE HIGH PRESSURE HAS DEVELOPED ACROSS THE NC/SC PIEDMONT REGION. WINDS ARE LIGHTER NEAR THIS RIDGE...AND THIS SHOULD HELP INSULATE THE REGION FROM ANY STRONGER WIND SPEEDS UNTIL TONIGHT. NORTHWEST WINDS IN THE 15-20 KT RANGE THIS MORNING WILL COME DOWN MORE INTO THE 15 KT RANGE THIS AFTERNOON...BUT INCREASING RAPIDLY THIS EVENING AS A STRONG UPPER LEVEL DISTURBANCE SHOOTS OFF THE COAST AND TREMENDOUSLY COLD AIR BEGINS TO POUR OFF THE COAST AND OVER THE COASTAL WATERS. THIS IS WHEN WINDS COULD INCREASE TO GALE FORCE FOR SEVERAL HOURS. SEAS RANGE FROM 2-4 FT ACROSS THE COASTAL WATERS THIS MORNING WITH LITTLE CHANGE EXPECTED THROUGH THE DAY. SEAS WILL REALLY INCREASE TONIGHT ESPECIALLY FOR LOCATIONS GREATER THAN 5-10 MILES FROM THE COAST DUE TO INCREASING EFFECTIVE FETCH LENGTH WITH THE NORTHWEST WINDS. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 AM MONDAY...STRONG GRADIENT AND DEEP MIXING CAUSED BY EXTREME COLD/STEEP LAPSE RATES WILL SPONSOR STRONG WINDS FOR MOST OF THE PERIOD. THIS WILL BE MOST PREVALENT ON TUESDAY WHEN THE COLD AIR AND GRADIENT WILL BE AT THEIR STRONGEST. GUSTS TO GALE FORCE TOUGH TO RULE OUT BUT CURRENT WRF FORECAST CAPS 850MB FLOW AT 30KT. THE SURFACE GRADIENT AND GUSTINESS RELATED TO THE LOW LEVEL JETTING WILL BOTH DECREASE TUESDAY NIGHT AS HIGH PRESSURE BUILDS INTO FLORIDA AND NE GOMEX...FLAGS WILL BE ABLE TO BE LOWERED. THIS HIGH NOW GETS QUICKLY SUPPRESSED TO THE SOUTH BY WED AFTERNOON BRINGING LIGHT WINDS THAT WILL BACK TO SWRLY. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 3 AM MONDAY...A MODERATE OFFSHORE/NW GRADIENT WIND REMAINS IN PLACE EARLY THURSDAY BUT A QUICK ABATEMENT TO AROUND 10KT BY AFTERNOON IS EXPECTED AS HIGH PRESSURE SETTLES ACROSS FL AND NE GOMEX. AS THE ANTICYCLONE PROGRESSES EAST AND ENDS UP NE OF BAHAMAS BY FRIDAY WIND LOCALLY BACKS TO SW WHILE SPEEDS REMAIN FAIRLY CONSTANT. SEAS COMPRISED OF MAINLY SHORT PERIOD WIND WAVES AND WILL AVG 2 TO 3 OR 2 TO 4 FT THROUGH THE PERIOD. && .FIRE WEATHER... THE DRIEST AIR OF THE SEASON WILL CONTINUE TO MOVE INTO THE AREA TODAY AND PERSIST INTO MID WEEK. THIS DRY AIR COUPLED WITH GUSTY NW WINDS MAY SERVE TO INCREASE THE FIRE DANGER ACROSS THE AREA. THE WORST OF THESE CONDITIONS ARE EXPECTED ON TUESDAY. MINIMUM RELATIVE HUMIDITY WILL BE NEAR OR BELOW CRITICAL VALUES AND WINDS WILL BE CLOSE TO THRESHOLD AS WELL...MAINLY IN GUSTS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...GALE WARNING FROM 6 PM THIS EVENING TO 7 AM EST TUESDAY FOR AMZ250-252-254-256. && $$ NEAR TERM...TRA SHORT TERM...MBB LONG TERM...MBB AVIATION...MRR FIRE WEATHER...RJD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
919 AM EST MON JAN 2 2012 .SYNOPSIS... ARCTIC HIGH PRESSURE WILL BRING COLD AND DRY CONDITIONS THROUGH MID WEEK WITH BRISK NORTHWEST WINDS. THE COLDEST TEMPERATURES SINCE LAST WINTER ARE EXPECTED TUESDAY NIGHT WITH LOWS IN THE TEENS OR LOWER 20S EXPECTED. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH WEDNESDAY...MODERATING LATE IN THE WEEK AND THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 930 AM MONDAY...THE FIRST COLD FRONT IS NOW WELL OFFSHORE AND COOLER NORTHWEST WINDS COVER THE CAROLINAS. THE STRONG NORTHWEST FLOW ACROSS THE MOUNTAINS HAS SET UP A LEE-SIDE TROUGH EXTENDING FROM ROANOKE TO HICKORY TO GREENVILLE SC...AND IN RESPONSE A MESOSCALE RIDGE HAS POKED UP THROUGH THE SC/NC PIEDMONT REGION. THIS EFFECT APPEARS TO BE WELL-MODELED IN THE LATEST RUC MODEL WHICH SHOWS LIGHTER WINDS THAN INITIALLY EXPECTED ACROSS THE EASTERN CAROLINAS THIS AFTERNOON. MORE IMPORTANTLY TO OUR FORECAST...THE 12Z BALLOON SOUNDINGS FROM MOREHEAD CITY...CHARLESTON SC...AND GREENSBORO SHOWED THE LOWER ATMOSPHERE UP TO THE 850 MB LAYER AVERAGED 2 DEGREES FAHRENHEIT WARMER THAN ANY MODEL HAD FORECAST THIS MORNING. WE HAVE RAISED HIGHS NOT-COINCIDENTALLY BY 2 DEGREES ACROSS THE BOARD TODAY...WITH MID 50S NOW EXPECTED FOR MOST AREAS. NO CHANGES ARE EXPECTED FOR TONIGHT. AS STRONG UPPER LEVEL TROUGH WILL PUSH OFF THE COAST OVERNIGHT WITH TREMENDOUS COLD ADVECTION DEVELOPING. 850 MB TEMPERATURES WILL FALL FROM AROUND -5C TO -6C THIS EVENING TO A BONE-CHILLING -13C BY DAYBREAK TUESDAY. A DEEPLY-MIXED BOUNDARY LAYER WILL BE TOPPED OFF BY SOME HIGH STRATOCUMULUS/LOW ALTOCUMULUS CLOUDS TONIGHT WHICH HAPPEN TO FORM RIGHT WITHIN THE -12C TO -18C TEMPERATURES FOR EFFICIENT DENDRITIC SNOW CRYSTAL GROWTH. A DEEP AND VERY DRY SUBCLOUD LAYER SHOULD BE ENOUGH TO PREVENT ANY SNOW FLURRIES FROM REACHING THE GROUND OVER OUR PORTION OF THE CAROLINAS...BUT WE WILL LOOK AGAIN AT THE 12Z GUIDANCE FOR ANY DISCERNIBLE TRENDS IN BOUNDARY LAYER MOISTURE CONTENT TONIGHT. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 AM MONDAY...RAW AND BITTERLY COLD TUESDAY WITH HIGHS IN THE 30S AND WIND CHILLS STUCK IN THE 20S ALL DAY FOR MOST OF THE REGION. THE REGION WILL BE IN THE THROES OF ARCTIC AIR THROUGH THE PERIOD...BUT TUESDAY AND TUESDAY NIGHT WILL BRING THE COLDEST OF THE COLD. FIERCE COLD ADVECTION SHUTS OFF EARLY TUESDAY WITH THE PASSING OF THE LOW LEVEL THERMAL TROUGH. SAID TROUGH WILL HAVE 850MB TEMPS BOTTOMED OUT AT AN IMPRESSIVE -13C OR ABOUT 9F. THIS IS COLD ENOUGH THAT DESPITE A GOOD 6-7KFT OF MIXING HIGH TEMPERATURES WILL STAY IN THE 30S. GUSTY NW WINDS COULD EASILY REACH 30 MPH AT TIMES KEEPING THE WIND CHILL NOT ONLY BELOW FREEZING BUT POSSIBLY IN THE 20S ALL AFTERNOON. SINGLE DIGIT DEWPOINTS PAIRED WITH THE WIND WILL MAKE FOR SOME FIRE WX CONCERNS AS WELL. TUESDAY NIGHT WILL BE THE COLDEST PERIOD OF THE ARCTIC INVASION...BUT THERE IS SOME UNCERTAINTY ABOUT HOW IDEALIZED OF A RADIATIONAL COOLING SETUP IS IN PLACE. GUIDANCE SUGGESTING THAT THE HIGH MAY BE SUPPRESSED WELL ENOUGH TO THE SOUTH TO KEEP A FEW MPH OF WIND ALL NIGHT. INDEED FCST SOUNDINGS DO NOT SHOW THE VERY STEEP SFC BASED INVERSION TYPICAL OF AN ARCTIC RAD COOLING NIGHT. WITH THE HIGH OFF TO THE SOUTH THERE IS A SMALL SOUTHERLY COMPONENT TO THE SURFACE FLOW BY WED. MIXING WILL BE MORE SHALLOW AS COMPARED TO TUESDAY SO ANY WARMUP WILL BE QUITE GRADUAL. WEDNESDAY HIGHS IN THE UPPER 40S. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 3 AM MONDAY...SHARP UPPER TROUGH OVER THE NORTHEASTERN U.S. WILL BE LIFTING OUT ON THU ALLOWING FOR WEAK HEIGHT RISES OVER MUCH OF THE EAST WHILE WEAK SFC RIDGE BUILDS IN. THE HIGH PROGRESSES EAST AND END SUP OFF THE COAST BY FRIDAY NIGHT ALLOWING A RETURN OF ABOVE CLIMO TEMPS AND SOME MOISTURE ADVECTION. A VERY WEAK SOUTHERN BRANCH FEATURE NOW STAYS FAR ENOUGH TO OUR SOUTH OVER THE WEEKEND TO BE OF ANY CONSEQUENCE. A COLD FRONT MAY ENTER AND STALL ACROSS THE AREA ON SUNDAY...BEING LARGELY LINED UP WITH THE WSW FLOW ALOFT. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... AS OF 12Z...A COLD FRONT HAS MOVED OFFSHORE AND IR SATELLITE LOOPS INDICATE CLEAR SKIES IN THE WAKE OF THE FRONT. WITH AN EVEN DRIER AIRMASS MOVING INTO THE TERMINALS THERE IS HIGH CONFIDENCE OF VFR/CLEAR SKIES THROUGH THIS AFTERNOON. GUSTY NORTHWEST WINDS WILL GRADUALLY ABATE BY NOON. WINDS WILL BECOME PROGRESSIVELY WESTERLY BY AFTERNOON. WINDS WILL FURTHER DECREASE TO 5-7 KNOTS AND BECOME WEST-SOUTHWEST TO WEST BY LATE AFTERNOON/EARLY EVENING AS ANOTHER COLD FRONT APPROACHES. THE FRONT SHOULD MOVE THROUGH ALL TERMINALS FROM NORTHWEST TO SOUTHEAST DURING THE EVENING. STRONG LIFT IS INDICATED WITH THE FRONT BUT MOISTURE IS LIMITED. DO NOT EXPECT ANY PRECIPITATION BUT THERE COULD BE A SHORT PERIOD OF CEILINGS AROUND 5K. WINDS WILL SHIFT BACK TO THE NORTHWEST WITH FROPA AS SKIES CLEAR. NOTE...DUE TO AN ASOS OUTAGE THE KFLO TAF WILL INDICATE AMD NOT SKED UNTIL OBSERVATIONS ARE AGAIN AVAILABLE. EXTENDED OUTLOOK...VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 930 AM MONDAY...THE COLD FRONT IS WELL OFFSHORE AND COOL NORTHWEST WINDS ARE IN PLACE ACROSS THE COASTAL WATERS. THE COLD FRONT OFFSHORE IS A PRESSURE TROUGH ITSELF...AND THERE IS A LEE-SIDE TROUGH OF LOW PRESSURE IN THE NC/SC FOOTHILLS AS WELL. BETWEEN THESE TWO SYSTEMS A SMALL-SCALE RIDGE OF RELATIVE HIGH PRESSURE HAS DEVELOPED ACROSS THE NC/SC PIEDMONT REGION. WINDS ARE LIGHTER NEAR THIS RIDGE...AND THIS SHOULD HELP INSULATE THE REGION FROM ANY STRONGER WIND SPEEDS UNTIL TONIGHT. NORTHWEST WINDS IN THE 15-20 KT RANGE THIS MORNING WILL COME DOWN MORE INTO THE 15 KT RANGE THIS AFTERNOON...BUT INCREASING RAPIDLY THIS EVENING AS A STRONG UPPER LEVEL DISTURBANCE SHOOTS OFF THE COAST AND TREMENDOUSLY COLD AIR BEGINS TO POUR OFF THE COAST AND OVER THE COASTAL WATERS. THIS IS WHEN WINDS COULD INCREASE TO GALE FORCE FOR SEVERAL HOURS. SEAS RANGE FROM 2-4 FT ACROSS THE COASTAL WATERS THIS MORNING WITH LITTLE CHANGE EXPECTED THROUGH THE DAY. SEAS WILL REALLY INCREASE TONIGHT ESPECIALLY FOR LOCATIONS GREATER THAN 5-10 MILES FROM THE COAST DUE TO INCREASING EFFECTIVE FETCH LENGTH WITH THE NORTHWEST WINDS. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 AM MONDAY...STRONG GRADIENT AND DEEP MIXING CAUSED BY EXTREME COLD/STEEP LAPSE RATES WILL SPONSOR STRONG WINDS FOR MOST OF THE PERIOD. THIS WILL BE MOST PREVALENT ON TUESDAY WHEN THE COLD AIR AND GRADIENT WILL BE AT THEIR STRONGEST. GUSTS TO GALE FORCE TOUGH TO RULE OUT BUT CURRENT WRF FORECAST CAPS 850MB FLOW AT 30KT. THE SURFACE GRADIENT AND GUSTINESS RELATED TO THE LOW LEVEL JETTING WILL BOTH DECREASE TUESDAY NIGHT AS HIGH PRESSURE BUILDS INTO FLORIDA AND NE GOMEX...FLAGS WILL BE ABLE TO BE LOWERED. THIS HIGH NOW GETS QUICKLY SUPPRESSED TO THE SOUTH BY WED AFTERNOON BRINGING LIGHT WINDS THAT WILL BACK TO SWRLY. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 3 AM MONDAY...A MODERATE OFFSHORE/NW GRADIENT WIND REMAINS IN PLACE EARLY THURSDAY BUT A QUICK ABATEMENT TO AROUND 10KT BY AFTERNOON IS EXPECTED AS HIGH PRESSURE SETTLES ACROSS FL AND NE GOMEX. AS THE ANTICYCLONE PROGRESSES EAST AND ENDS UP NE OF BAHAMAS BY FRIDAY WIND LOCALLY BACKS TO SW WHILE SPEEDS REMAIN FAIRLY CONSTANT. SEAS COMPRISED OF MAINLY SHORT PERIOD WIND WAVES AND WILL AVG 2 TO 3 OR 2 TO 4 FT THROUGH THE PERIOD. && .FIRE WEATHER... THE DRIEST AIR OF THE SEASON WILL CONTINUE TO MOVE INTO THE AREA TODAY AND PERSIST INTO MID WEEK. THIS DRY AIR COUPLED WITH GUSTY NW WINDS MAY SERVE TO INCREASE THE FIRE DANGER ACROSS THE AREA. THE WORST OF THESE CONDITIONS ARE EXPECTED ON TUESDAY. MINIMUM RELATIVE HUMIDITY WILL BE NEAR OR BELOW CRITICAL VALUES AND WINDS WILL BE CLOSE TO THRESHOLD AS WELL...MAINLY IN GUSTS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...GALE WARNING FROM 6 PM THIS EVENING TO 7 AM EST TUESDAY FOR AMZ250-252-254-256. && $$ NEAR TERM...TRA SHORT TERM...MBB LONG TERM...MBB AVIATION...MRR FIRE WEATHER...RJD
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1225 PM EST MON JAN 2 2012 .SYNOPSIS... STRONG UPPER LEVEL LOW AND ARCTIC AIRMASS RESULTS IN WIND BLOWN SNOW SHOWERS THROUGH TUESDAY. WEAKER COLD FRONT MOVES THROUGH WEDNESDAY. DRY WITH MODERATING TEMPERATURES FOR THE END OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... LATEST RADAR MOSAIC SHOWS AREAS OF SNOW...SOME HEAVY...MOVING EAST ACROSS THE FORECAST AREA. RADAR INDICATES A FEW MESOSCALE FEATURES IN THE FLOW...WITH SOME OF THE HEAVIER SNOW BEING PRODUCED BY THESE FEATURES. UPPER LEVEL FEATURE...WHICH IS STILL LOCATED NORTHWEST OF REGION... IS EXPECTED TO APPROACH THE AREA LATER TODAY. THIS SHOULD FURTHER ENHANCE THE SNOW. CURRENT FORECAST IS PRETTY MUCH ON TRACK. HOWEVER...WILL TAKE A LOOK AT SNOWFALL FORECAST TO SEE IF WE MIGHT NEED TO BUMP IT UP IN A FEW LOCATIONS FOR TODAY. PREVIOUS DISCUSSION... IR SATELLITE IMAGERY SHOWING MID AND LOW LEVEL CLOUD DECK APPROACHING WESTERN FLANKS. A RIDGE OF LOW H85 MOISTURE WAS EVIDENT AHEAD OF THIS CLOUD DECK...WHICH LED TO CLEARING OVER CENTRAL PORTIONS OF CWA. THIS SHOULD FILL IN QUICKLY OVER NEXT SEVERAL HOURS. RUC H85 MOISTURE ACCURATELY DEPICTING MOISTURE ASSOCIATED WITH LOW AND MID LEVEL CLOUDS STREAMING DOWNSTREAM OF THE GREAT LAKES. CURRENT H85 TEMPS FROM RUC ARE ABOUT -9C. WITH RUC H925 TEMPS ABOUT -3C...LAPSE RATES ARE STEEPENING AND SHOULD CONTINUE WITH ADDITIONAL CAA. STEEP LAPSE RATES AND ADDED DEEP MOISTURE WILL ONLY ADD TO THE SPATIAL COVERAGE OF SNOW SHOWERS ALREADY DEVELOPING NW INTO CENTRAL OHIO. KEPT SNOW TOTALS CLOSE TO PREVIOUS FORECAST...BUT DID TWEAK EKN VICINITY UP A BIT AS THAT AREA RECEIVED A QUICK 1.5 INCHES OF NEW SNOW BEFORE MIDNIGHT...THIS SNOW COMING BEFORE THE REAL MOISTURE ARRIVES. PLAN TO KEEP ADVISORIES THE SAME AS PREVIOUS FORECAST. BELIEVE OUR NW WV COUNTIES COULD COME CLOSE TO MEETING ADVISORY CRITERIA FOR SNOW TOTALS IN 12HR TIME FRAME...BUT WOULD LIKE TO SEE TRENDS IN INITIAL SNOW DEVELOPMENT FIRST. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... COLD AIR ADVECTION CONTINUES INTO TUESDAY AFTERNOON. MODELS SHOWING LAKE PLUMES ALSO EFFECTING THE AREA...ALTHOUGH DEEPER MOISTURE PULLS OUT IN THE MORNING. SHOULD BE PLENTY OF SNOW FLAKES AROUND...BUT ACCUMULATIONS SHOULD BE LIMITED...WITH THE BEST ACCUMULATIONS IN THE LAKE PLUMES. WARM AIR ADVECTION THEN SETS IN FOR TUESDAY NIGHT...AND SHOULD BRING AN END TO THE SNOW. ANOTHER MUCH WEAKER SYSTEM SKIRTS NORTHERN PORTIONS OF THE REGION ON WEDNESDAY AND WEDNESDAY NIGHT. COULD SEE SOME LIGHT SNOW IN THE NORTHERN COUNTIES...BUT THIS SYSTEM IS FAIRLY MOISTURE STARVED...SO WILL KEEP POPS LOW. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... ONE LAST UPPER LEVEL S/W TROF MOVES SE THROUGH THE AREA IN THE LARGER SCALE NW FLOW ALOFT RIGHT AT THE START OF THE PERIOD. UPSLOPE FLOW IN ITS WAKE SHOULD BRING LIGHT SNOW SHOWERS OR FLURRIES TO THE MOUNTAINS WED NT INTO THU MORNING. WITH HEIGHTS QUICKLY LIFTING THU...EXPECT THE AIR MASS IN THE WAKE OF THE FRONT TO NOT BE QUITE AS COLD AS ITS PREDECESSOR...AND THE UPSLOPE EVENT NO WHERE NEAR THE DURATION OR MAGNITUDE OF ITS PREDECESSOR. HIGH PRESSURE CROSSES THU NT...FOLLOWED BY SW FLOW ON ITS BACK SIDE FRI INTO THE WEEKEND. NEXT NORTHERN STREAM UPPER LEVEL S/W TROUGH DRIVES SURFACE COLD FRONT THROUGH THE AREA OVER THE WEEKEND...WITH MODEL DIFFERENCES ON TIMING. MOISTURE GETS DRAWN UP AHEAD OF THE FRONT INTO THE FORECAST AREA JUST AS THE FRONT APPROACHES SAT MORNING. AIR MASS BEHIND FRONT DOES NOT IT LEAST INITIALLY APPEAR TO BE AS COLD AS THE ONE CHARGING THROUGH EARLY THIS WEEK. UPPER LOW FORMS OVER THE SWRN CONUS EARLY IN THE WEEKEND IN RESPONSE TO RIDGING OFF THE W COAST. MODELS THEN START TO EJECT THIS LOW NEWD LATE IN THE WEEKEND WITH SOME TIMING DIFFERENCES IN TANDEM WITH SIMILAR DIFFERENCES IN THE NORTHERN STREAM. BLENDED IN MEX / HPC FOR TEMPERATURES...NO SIGNIFICANT CHANGES. && .AVIATION /18Z MONDAY THROUGH FRIDAY/... LOW LEVEL MOISTURE PLUME CONTINUES TO MOVE SOUTHEAST ACROSS OUR AREA. RADAR AND SATELLITE IMAGERY SHOWS SEVERAL MID-LEVEL TROFS PUSHING ACROSS AREA...WITH THE MAIN SHORTWAVE OVER INDIANA. IN RESPONSE TO MOISTURE AND FEATURES...SCATTERED SNOW SHOWERS WITH MVFR...ISOLD IFR...CONDITIONS WERE BEING REPORTED. VFR CONDITIONS PREVAILED OUTSIDE OF THE SNOW. THE MAIN WAVE IS EXPECTED TO PUSH SOUTHEAST ACROSS AREA BETWEEN 21Z AND 06Z TUESDAY. AS THIS FEATURE PUSHES ACROSS AREA...EXPECT CONDITIONS ACROSS THE LOWLANDS WILL DETERIORATE TO MVFR...ISOLD IFR IN SNOW SHOWERS BY 22Z...WITH IFR...ISOLD LIFR...CONDITIONS IN THE MOUNTAINS. THESE CONDITIONS ARE EXPECTED TO CONTINUE THROUGH 15Z...WITH CONDITIONS EXPECTED TO SLOWLY IMPROVE AFTER THAT TIME. EXPECT GUSTY WESTERLY WINDS WILL SLOWLY DECREASE THRU 01Z...WITH GUSTY WINDS CONTINUING ACROSS THE HIGHER ELEVATIONS UNTIL 12Z. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY... FORECAST CONFIDENCE:MODERATE. ALTERNATE SCENARIOS: DRY AIR IN THE LOWER LEVELS COULD ACT TO HOLD VFR/MVFR CONDITIONS FOR A LONGER PERIOD OF TIME...BEFORE DETERIORATING LATER TODAY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05 EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00 CRW CONSISTENCY L L L M L L M L L L L L HTS CONSISTENCY L M M M M M L M M M M M BKW CONSISTENCY M M L L L L L L L L L L EKN CONSISTENCY M M L L L L M L L L L L PKB CONSISTENCY L M M M M L L M L L L L CKB CONSISTENCY L L M M L L L L L L L L AFTER 18Z TUESDAY... IFR IN WIDELY SCATTERED MOUNTAIN SNOW SHOWERS POSSIBLE EARLY TUESDAY AFTERNOON. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...WINTER WEATHER ADVISORY UNTIL NOON EST TUESDAY FOR WVZ015-016- 018-024>031-033-034. WINTER WEATHER ADVISORY UNTIL 4 PM EST TUESDAY FOR WVZ032- 035>040-046-047. OH...NONE. KY...NONE. VA...WINTER WEATHER ADVISORY UNTIL NOON EST TUESDAY FOR VAZ003-004. && $$ SYNOPSIS...TRM/RPY/TAX NEAR TERM...JSH/TAX SHORT TERM...RPY LONG TERM...TRM AVIATION...JSH
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1036 AM EST MON JAN 2 2012 .SYNOPSIS... STRONG UPPER LEVEL LOW AND ARCTIC AIRMASS RESULTS IN WIND BLOWN SNOW SHOWERS THROUGH TUESDAY. WEAKER COLD FRONT MOVES THROUGH WEDNESDAY. DRY WITH MODERATING TEMPERATURES FOR THE END OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... LATEST RADAR MOSAIC SHOWS AREAS OF SNOW...SOME HEAVY...MOVING EAST ACROSS THE FORECAST AREA. RADAR INDICATES A FEW MESOSCALE FEATURES IN THE FLOW...WITH SOME OF THE HEAVIER SNOW BEING PRODUCED BY THESE FEATURES. UPPER LEVEL FEATURE...WHICH IS STILL LOCATED NORTHWEST OF REGION... IS EXPECTED TO APPROACH THE AREA LATER TODAY. THIS SHOULD FURTHER ENHANCE THE SNOW. CURRENT FORECAST IS PRETTY MUCH ON TRACK. HOWEVER...WILL TAKE A LOOK AT SNOWFALL FORECAST TO SEE IF WE MIGHT NEED TO BUMP IT UP IN A FEW LOCATIONS FOR TODAY. PREVIOUS DISCUSSION... IR SATELLITE IMAGERY SHOWING MID AND LOW LEVEL CLOUD DECK APPROACHING WESTERN FLANKS. A RIDGE OF LOW H85 MOISTURE WAS EVIDENT AHEAD OF THIS CLOUD DECK...WHICH LED TO CLEARING OVER CENTRAL PORTIONS OF CWA. THIS SHOULD FILL IN QUICKLY OVER NEXT SEVERAL HOURS. RUC H85 MOISTURE ACCURATELY DEPICTING MOISTURE ASSOCIATED WITH LOW AND MID LEVEL CLOUDS STREAMING DOWNSTREAM OF THE GREAT LAKES. CURRENT H85 TEMPS FROM RUC ARE ABOUT -9C. WITH RUC H925 TEMPS ABOUT -3C...LAPSE RATES ARE STEEPENING AND SHOULD CONTINUE WITH ADDITIONAL CAA. STEEP LAPSE RATES AND ADDED DEEP MOISTURE WILL ONLY ADD TO THE SPATIAL COVERAGE OF SNOW SHOWERS ALREADY DEVELOPING NW INTO CENTRAL OHIO. KEPT SNOW TOTALS CLOSE TO PREVIOUS FORECAST...BUT DID TWEAK EKN VICINITY UP A BIT AS THAT AREA RECEIVED A QUICK 1.5 INCHES OF NEW SNOW BEFORE MIDNIGHT...THIS SNOW COMING BEFORE THE REAL MOISTURE ARRIVES. PLAN TO KEEP ADVISORIES THE SAME AS PREVIOUS FORECAST. BELIEVE OUR NW WV COUNTIES COULD COME CLOSE TO MEETING ADVISORY CRITERIA FOR SNOW TOTALS IN 12HR TIME FRAME...BUT WOULD LIKE TO SEE TRENDS IN INITIAL SNOW DEVELOPMENT FIRST. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... COLD AIR ADVECTION CONTINUES INTO TUESDAY AFTERNOON. MODELS SHOWING LAKE PLUMES ALSO EFFECTING THE AREA...ALTHOUGH DEEPER MOISTURE PULLS OUT IN THE MORNING. SHOULD BE PLENTY OF SNOW FLAKES AROUND...BUT ACCUMULATIONS SHOULD BE LIMITED...WITH THE BEST ACCUMULATIONS IN THE LAKE PLUMES. WARM AIR ADVECTION THEN SETS IN FOR TUESDAY NIGHT...AND SHOULD BRING AN END TO THE SNOW. ANOTHER MUCH WEAKER SYSTEM SKIRTS NORTHERN PORTIONS OF THE REGION ON WEDNESDAY AND WEDNESDAY NIGHT. COULD SEE SOME LIGHT SNOW IN THE NORTHERN COUNTIES...BUT THIS SYSTEM IS FAIRLY MOISTURE STARVED...SO WILL KEEP POPS LOW. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... ONE LAST UPPER LEVEL S/W TROF MOVES SE THROUGH THE AREA IN THE LARGER SCALE NW FLOW ALOFT RIGHT AT THE START OF THE PERIOD. UPSLOPE FLOW IN ITS WAKE SHOULD BRING LIGHT SNOW SHOWERS OR FLURRIES TO THE MOUNTAINS WED NT INTO THU MORNING. WITH HEIGHTS QUICKLY LIFTING THU...EXPECT THE AIR MASS IN THE WAKE OF THE FRONT TO NOT BE QUITE AS COLD AS ITS PREDECESSOR...AND THE UPSLOPE EVENT NO WHERE NEAR THE DURATION OR MAGNITUDE OF ITS PREDECESSOR. HIGH PRESSURE CROSSES THU NT...FOLLOWED BY SW FLOW ON ITS BACK SIDE FRI INTO THE WEEKEND. NEXT NORTHERN STREAM UPPER LEVEL S/W TROUGH DRIVES SURFACE COLD FRONT THROUGH THE AREA OVER THE WEEKEND...WITH MODEL DIFFERENCES ON TIMING. MOISTURE GETS DRAWN UP AHEAD OF THE FRONT INTO THE FORECAST AREA JUST AS THE FRONT APPROACHES SAT MORNING. AIR MASS BEHIND FRONT DOES NOT IT LEAST INITIALLY APPEAR TO BE AS COLD AS THE ONE CHARGING THROUGH EARLY THIS WEEK. UPPER LOW FORMS OVER THE SWRN CONUS EARLY IN THE WEEKEND IN RESPONSE TO RIDGING OFF THE W COAST. MODELS THEN START TO EJECT THIS LOW NEWD LATE IN THE WEEKEND WITH SOME TIMING DIFFERENCES IN TANDEM WITH SIMILAR DIFFERENCES IN THE NORTHERN STREAM. BLENDED IN MEX / HPC FOR TEMPERATURES...NO SIGNIFICANT CHANGES. && .AVIATION /16Z MONDAY THROUGH FRIDAY/... LOW LEVEL MOISTURE PLUME EVIDENT ON WATER VAPOR IMAGERY STARTING MOVE INTO OUR AREA. HAVE CIGS DROPPING TO MVFR W TO E OVER NEXT FEW HOURS WITH ARRIVAL OF THIS MOISTURE. WILL KEEP MVFR CIGS OVER LOWLAND COUNTIES THROUGH TODAY...HOWEVER VSBYS WILL DROP TO IFR OR LOWER IN SHSN TODAY AND TONIGHT. EXPECT VSBYS TO BOUNCE UP AND DOWN TODAY...THUS WILL INCLUDE TEMPO GROUPS TO COVER THIS. IN THE MOUNTAINS OF WV EXPECTING CIGS AND VSBYS TO BE IFR AND BOUNCING IN AND OUT OF LIFR IN INDIVIDUAL SHSN. IFR TO LIFR COULD PERSIST IN THE MOUNTAINS FOR QUITE SOME TIME...EVEN BEYOND THE SCOPE OF THIS ISSUANCE. EXPECTING A SLOW DECREASE IN THE WIND GUSTS WHICH ARE ALREADY EVIDENT IN THE OBSERVATIONS. SUSTAINED WINDS ARE NOT EXPECTED TO DROP BELOW 12KTS TO 15KTS THROUGH 00Z TUESDAY. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY... FORECAST CONFIDENCE:HIGH. ALTERNATE SCENARIOS: CIGS OVER THE LOWLANDS MAY DROP TO IFR WITH LOW LEVEL MOISTURE THROUGH TODAY. 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 M L L M M M M M L L L L HTS CONSISTENCY M M L L L M M L L L L L BKW CONSISTENCY L L M M L L L L L L L L EKN CONSISTENCY L M M M L L L L L L L L PKB CONSISTENCY M L L M M M M M L L L L CKB CONSISTENCY L L L M M M M M L L L L AFTER 18Z TUESDAY... IFR IN SNOW SHOWERS POSSIBLE TUESDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...WINTER WEATHER ADVISORY UNTIL NOON EST TUESDAY FOR WVZ015-016- 018-024>031-033-034. WINTER WEATHER ADVISORY UNTIL 4 PM EST TUESDAY FOR WVZ032- 035>040-046-047. OH...NONE. KY...NONE. VA...WINTER WEATHER ADVISORY UNTIL NOON EST TUESDAY FOR VAZ003-004. && $$ SYNOPSIS...TRM/RPY/TAX NEAR TERM...JSH/TAX SHORT TERM...RPY LONG TERM...TRM AVIATION...TAX
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
447 AM EST MON JAN 2 2012 .SYNOPSIS... STRONG UPPER LEVEL LOW AND ARCTIC AIRMASS RESULTS IN WIND BLOWN SNOW SHOWERS THROUGH TUESDAY. WEAKER COLD FRONT MOVES THROUGH WEDNESDAY. DRY WITH MODERATING TEMPERATURES FOR THE END OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... IR SATELLITE IMAGERY SHOWING MID AND LOW LEVEL CLOUD DECK APPROACHING WESTERN FLANKS. A RIDGE OF LOW H85 MOISTURE WAS EVIDENT AHEAD OF THIS CLOUD DECK...WHICH LED TO CLEARING OVER CENTRAL PORTIONS OF CWA. THIS SHOULD FILL IN QUICKLY OVER NEXT SEVERAL HOURS. RUC H85 MOISTURE ACCURATELY DEPICTING MOISTURE ASSOCIATED WITH LOW AND MID LEVEL CLOUDS STREAMING DOWNSTREAM OF THE GREAT LAKES. CURRENT H85 TEMPS FROM RUC ARE ABOUT -9C. WITH RUC H925 TEMPS ABOUT -3C...LAPSE RATES ARE STEEPENING AND SHOULD CONTINUE WITH ADDITIONAL CAA. STEEP LAPSE RATES AND ADDED DEEP MOISTURE WILL ONLY ADD TO THE SPATIAL COVERAGE OF SNOW SHOWERS ALREADY DEVELOPING NW INTO CENTRAL OHIO. KEPT SNOW TOTALS CLOSE TO PREVIOUS FORECAST...BUT DID TWEAK EKN VICINITY UP A BIT AS THAT AREA RECEIVED A QUICK 1.5 INCHES OF NEW SNOW BEFORE MIDNIGHT...THIS SNOW COMING BEFORE THE REAL MOISTURE ARRIVES. PLAN TO KEEP ADVISORIES THE SAME AS PREVIOUS FORECAST. BELIEVE OUR NW WV COUNTIES COULD COME CLOSE TO MEETING ADVISORY CRITERIA FOR SNOW TOTALS IN 12HR TIME FRAME...BUT WOULD LIKE TO SEE TRENDS IN INITIAL SNOW DEVELOPMENT FIRST. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... COLD AIR ADVECTION CONTINUES INTO TUESDAY AFTERNOON. MODELS SHOWING LAKE PLUMES ALSO EFFECTING THE AREA...ALTHOUGH DEEPER MOISTURE PULLS OUT IN THE MORNING. SHOULD BE PLENTY OF SNOW FLAKES AROUND...BUT ACCUMULATIONS SHOULD BE LIMITED...WITH THE BEST ACCUMULATIONS IN THE LAKE PLUMES. WARM AIR ADVECTION THEN SETS IN FOR TUESDAY NIGHT...AND SHOULD BRING AN END TO THE SNOW. ANOTHER MUCH WEAKER SYSTEM SKIRTS NORTHERN PORTIONS OF THE REGION ON WEDNESDAY AND WEDNESDAY NIGHT. COULD SEE SOME LIGHT SNOW IN THE NORTHERN COUNTIES...BUT THIS SYSTEM IS FAIRLY MOISTURE STARVED...SO WILL KEEP POPS LOW. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... ONE LAST UPPER LEVEL S/W TROF MOVES SE THROUGH THE AREA IN THE LARGER SCALE NW FLOW ALOFT RIGHT AT THE START OF THE PERIOD. UPSLOPE FLOW IN ITS WAKE SHOULD BRING LIGHT SNOW SHOWERS OR FLURRIES TO THE MOUNTAINS WED NT INTO THU MORNING. WITH HEIGHTS QUICKLY LIFTING THU...EXPECT THE AIR MASS IN THE WAKE OF THE FRONT TO NOT BE QUITE AS COLD AS ITS PREDECESSOR...AND THE UPSLOPE EVENT NO WHERE NEAR THE DURATION OR MAGNITUDE OF ITS PREDECESSOR. HIGH PRESSURE CROSSES THU NT...FOLLOWED BY SW FLOW ON ITS BACK SIDE FRI INTO THE WEEKEND. NEXT NORTHERN STREAM UPPER LEVEL S/W TROUGH DRIVES SURFACE COLD FRONT THROUGH THE AREA OVER THE WEEKEND...WITH MODEL DIFFERENCES ON TIMING. MOISTURE GETS DRAWN UP AHEAD OF THE FRONT INTO THE FORECAST AREA JUST AS THE FRONT APPROACHES SAT MORNING. AIR MASS BEHIND FRONT DOES NOT IT LEAST INITIALLY APPEAR TO BE AS COLD AS THE ONE CHARGING THROUGH EARLY THIS WEEK. UPPER LOW FORMS OVER THE SWRN CONUS EARLY IN THE WEEKEND IN RESPONSE TO RIDGING OFF THE W COAST. MODELS THEN START TO EJECT THIS LOW NEWD LATE IN THE WEEKEND WITH SOME TIMING DIFFERENCES IN TANDEM WITH SIMILAR DIFFERENCES IN THE NORTHERN STREAM. BLENDED IN MEX / HPC FOR TEMPERATURES...NO SIGNIFICANT CHANGES. && .AVIATION /10Z MONDAY THROUGH FRIDAY/... LOW LEVEL MOISTURE PLUME EVIDENT ON WATER VAPOR IMAGERY STARTING MOVE INTO OUR AREA. HAVE CIGS DROPPING TO MVFR W TO E OVER NEXT FEW HOURS WITH ARRIVAL OF THIS MOISTURE. WILL KEEP MVFR CIGS OVER LOWLAND COUNTIES THROUGH TODAY...HOWEVER VSBYS WILL DROP TO IFR OR LOWER IN SHSN TODAY AND TONIGHT. EXPECT VSBYS TO BOUNCE UP AND DOWN TODAY...THUS WILL INCLUDE TEMPO GROUPS TO COVER THIS. IN THE MOUNTAINS OF WV EXPECTING CIGS AND VSBYS TO BE IFR AND BOUNCING IN AND OUT OF LIFR IN INDIVIDUAL SHSN. IFR TO LIFR COULD PERSIST IN THE MOUNTAINS FOR QUITE SOME TIME...EVEN BEYOND THE SCOPE OF THIS ISSUANCE. EXPECTING A SLOW DECREASE IN THE WIND GUSTS WHICH ARE ALREADY EVIDENT IN THE OBSERVATIONS. SUSTAINED WINDS ARE NOT EXPECTED TO DROP BELOW 12KTS TO 15KTS THROUGH 00Z TUESDAY. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY... FORECAST CONFIDENCE:HIGH. ALTERNATE SCENARIOS: CIGS OVER THE LOWLANDS MAY DROP TO IFR WITH LOW LEVEL MOISTURE THROUGH TODAY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE MON 01/02/12 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 M M M L L L L M L L L L HTS CONSISTENCY M M H M L L L L M M M M BKW CONSISTENCY L L M M M L M M L L L L EKN CONSISTENCY L L M M M L L L L L L L PKB CONSISTENCY L L M M M M M M L L L L CKB CONSISTENCY L L M M M M M M L L L L AFTER 12Z TUESDAY... IFR IN SNOW SHOWERS POSSIBLE TUESDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO NOON EST TUESDAY FOR WVZ015-016-018-024>031-033-034. WINTER WEATHER ADVISORY UNTIL 4 PM EST TUESDAY FOR WVZ032- 035>040-046-047. OH...NONE. KY...NONE. VA...WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO NOON EST TUESDAY FOR VAZ003-004. && $$ SYNOPSIS...TRM/RPY/TAX NEAR TERM...TAX SHORT TERM...RPY LONG TERM...TRM AVIATION...TAX
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
330 AM EST MON JAN 2 2012 .SYNOPSIS... STRONG UPPER LEVEL LOW AND ARCTIC AIRMASS RESULTS IN WIND BLOWN SNOW SHOWERS THROUGH TUESDAY. WEAKER COLD FRONT MOVES THROUGH WEDNESDAY. DRY WITH MODERATING TEMPERATURES FOR THE END OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... 1230AM UPDATE... BUMPED UP POPS TO REPRESENT CURRENT RADAR TRENDS...ESPECIALLY IN SE OHIO WHERE LATEST RUC ALREADY SHOWING H85 MOISTURE ADVECTING IN. OTHERWISE...KEEPING PREVIOUS FORECAST ON TRACK. 930PM UPDATE... ADJUSTED THE SNOWFALL AMOUNTS DOWN IN NORTHWEST WEST VIRGINIA AND SOUTHEAST OHIO BY AN INCH OR SO IN TERMS OF STORM TOTAL. TEMPERATURES WERE GIVEN SOME TLC...BUT WERE LINING UP FAIRLY WELL AGAIN FOR THIS ISSUANCE. DESPITE READINGS NEAR 40F...ICE PELLETS AND SNOW HAD BEEN REPORTED FROM A FEW DIFFERENT SOURCES...AND CKB HAS -SN IN THE LATEST OB AT 36F. WILL EXPECT RADAR COVERAGE OF THE PRECIPITATION TO INCREASE IN THE COMING HOURS WITH THE MAIN TROUGH AXIS DIGGING INTO THE OHIO VALLEY. PREVIOUS DISCUSSION... THE UPPER SYSTEM WILL MOVE ACROSS THE MONDAY AFTERNOON. ABUNDANT LOW-LEVEL MOISTURE SHOULD COMBINE WITH FORCING ASSOCIATED WITH UPPER SYSTEM TO RESULT IN MEASURABLE SNOW ACROSS MOST OF THE REGION. UPSLOPE FLOW...ABUNDANT DEEP MOISTURE AND FAVORABLE TEMP PROFILE WILL COMBINE TO RESULT IN ENHANCED SNOWFALL IN THE FAVORED UPSLOPE REGION. PLAN TO LEAVE ADVISORIES UNCHANGED AS FORECASTED SNOW AMOUNTS SHOULD NOT REACH WARNING CRITERIA IN THE MOUNTAINS. PORTIONS OF NORTHERN WV AND SOUTHEAST OH...NEAR PKB...COULD SEE SNOWFALL AMOUNTS APPROACHING ADVISORY CRITERIA. AFTER COLLABORATING WITH NORTHERN NEIGHBORS...NO PLANS TO ADD THAT REGION TO THE ADVISORY AT THIS TIME. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... COLD AIR ADVECTION CONTINUES INTO TUESDAY AFTERNOON. MODELS SHOWING LAKE PLUMES ALSO EFFECTING THE AREA...ALTHOUGH DEEPER MOISTURE PULLS OUT IN THE MORNING. SHOULD BE PLENTY OF SNOW FLAKES AROUND...BUT ACCUMULATIONS SHOULD BE LIMITED...WITH THE BEST ACCUMULATIONS IN THE LAKE PLUMES. WARM AIR ADVECTION THEN SETS IN FOR TUESDAY NIGHT...AND SHOULD BRING AN END TO THE SNOW. ANOTHER MUCH WEAKER SYSTEM SKIRTS NORTHERN PORTIONS OF THE REGION ON WEDNESDAY AND WEDNESDAY NIGHT. COULD SEE SOME LIGHT SNOW IN THE NORTHERN COUNTIES...BUT THIS SYSTEM IS FAIRLY MOISTURE STARVED...SO WILL KEEP POPS LOW. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... ONE LAST UPPER LEVEL S/W TROF MOVES SE THROUGH THE AREA IN THE LARGER SCALE NW FLOW ALOFT RIGHT AT THE START OF THE PERIOD. UPSLOPE FLOW IN ITS WAKE SHOULD BRING LIGHT SNOW SHOWERS OR FLURRIES TO THE MOUNTAINS WED NT INTO THU MORNING. WITH HEIGHTS QUICKLY LIFTING THU...EXPECT THE AIR MASS IN THE WAKE OF THE FRONT TO NOT BE QUITE AS COLD AS ITS PREDECESSOR...AND THE UPSLOPE EVENT NO WHERE NEAR THE DURATION OR MAGNITUDE OF ITS PREDECESSOR. HIGH PRESSURE CROSSES THU NT...FOLLOWED BY SW FLOW ON ITS BACK SIDE FRI INTO THE WEEKEND. NEXT NORTHERN STREAM UPPER LEVEL S/W TROUGH DRIVES SURFACE COLD FRONT THROUGH THE AREA OVER THE WEEKEND...WITH MODEL DIFFERENCES ON TIMING. MOISTURE GETS DRAWN UP AHEAD OF THE FRONT INTO THE FORECAST AREA JUST AS THE FRONT APPROACHES SAT MORNING. AIR MASS BEHIND FRONT DOES NOT IT LEAST INITIALLY APPEAR TO BE AS COLD AS THE ONE CHARGING THROUGH EARLY THIS WEEK. UPPER LOW FORMS OVER THE SWRN CONUS EARLY IN THE WEEKEND IN RESPONSE TO RIDGING OFF THE W COAST. MODELS THEN START TO EJECT THIS LOW NEWD LATE IN THE WEEKEND WITH SOME TIMING DIFFERENCES IN TANDEM WITH SIMILAR DIFFERENCES IN THE NORTHERN STREAM. BLENDED IN MEX / HPC FOR TEMPERATURES...NO SIGNIFICANT CHANGES. && .AVIATION /09Z MONDAY THROUGH FRIDAY/... LOW LEVEL MOISTURE PLUME EVIDENT ON WATER VAPOR IMAGERY STARTING TO APPROACH CWA. HAVE CIGS DROPPING TO MVFR W TO E OVER NEXT FEW HOURS WITH ARRIVAL OF THIS MOISTURE. WILL KEEP MVFR CIGS OVER LOWLAND COUNTIES THROUGH TODAY...HOWEVER VSBYS WILL DROP TO IFR OR LOWER IN SHSN TODAY AND TONIGHT. EXPECT VSBYS TO BOUNCE UP AND DOWN TODAY...THUS WILL INCLUDE TEMPO GROUPS TO COVER THIS. IN THE MOUNTAINS OF WV EXPECTING CIGS AND VSBYS TO BE IFR AND BOUNCING IN AND OUT OF LIFR IN INDIVIDUAL SHSN. IFR TO LIFR COULD PERSIST IN THE MOUNTAINS FOR QUITE SOME TIME...EVEN BEYOND THE SCOPE OF THIS ISSUANCE. EXPECTING A SLOW DECREASE IN THE WIND GUSTS WHICH ARE ALREADY EVIDENT IN THE OBSERVATIONS. SUSTAINED WINDS ARE NOT EXPECTED TO DROP BELOW 12KTS TO 15KTS THROUGH 00Z TUESDAY. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY... FORECAST CONFIDENCE:HIGH. ALTERNATE SCENARIOS: CIGS OVER THE LOWLANDS MAY DROP TO IFR WITH LOW LEVEL MOISTURE THROUGH TODAY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE MON 01/02/12 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12 CRW CONSISTENCY H H M M M L L L L L M M HTS CONSISTENCY H H M M M M L L L L M M BKW CONSISTENCY M M M M H H M M M M L L EKN CONSISTENCY L L L M M M M L L L L L PKB CONSISTENCY M M M M L L L L L L M M CKB CONSISTENCY M M L M M M M M M M M M AFTER 06Z TUESDAY... IFR IN SNOW SHOWERS POSSIBLE TUESDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO NOON EST TUESDAY FOR WVZ015-016-018-024>031-033-034. WINTER WEATHER ADVISORY UNTIL 4 PM EST TUESDAY FOR WVZ032- 035>040-046-047. OH...NONE. KY...NONE. VA...WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO NOON EST TUESDAY FOR VAZ003-004. && $$ SYNOPSIS...TRM/RPY/TAX NEAR TERM...TAX SHORT TERM...RPY LONG TERM...TRM AVIATION...26/TAX
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1248 AM EST MON JAN 2 2012 .SYNOPSIS... STRONG UPPER LEVEL LOW AND ARCTIC AIRMASS RESULTS IN WIND BLOWN SNOW SHOWERS THIS MORNING THROUGH TUESDAY. WEAKER COLD FRONT MOVES THROUGH WEDNESDAY NIGHT. && .NEAR TERM /THROUGH TODAY/... 1230AM UPDATE... BUMPED UP POPS TO REPRESENT CURRENT RADAR TRENDS...ESPECIALLY IN SE OHIO WHERE LATEST RUC ALREADY SHOWING H85 MOISTURE ADVECTING IN. OTHERWISE...KEEPING PREVIOUS FORECAST ON TRACK. 930PM UPDATE... ADJUSTED THE SNOWFALL AMOUNTS DOWN IN NORTHWEST WEST VIRGINIA AND SOUTHEAST OHIO BY AN INCH OR SO IN TERMS OF STORM TOTAL. TEMPERATURES WERE GIVEN SOME TLC...BUT WERE LINING UP FAIRLY WELL AGAIN FOR THIS ISSUANCE. DESPITE READINGS NEAR 40F...ICE PELLETS AND SNOW HAD BEEN REPORTED FROM A FEW DIFFERENT SOURCES...AND CKB HAS -SN IN THE LATEST OB AT 36F. WILL EXPECT RADAR COVERAGE OF THE PRECIPITATION TO INCREASE IN THE COMING HOURS WITH THE MAIN TROUGH AXIS DIGGING INTO THE OHIO VALLEY. PREVIOUS DISCUSSION... THE UPPER SYSTEM WILL MOVE ACROSS THE MONDAY AFTERNOON. ABUNDANT LOW-LEVEL MOISTURE SHOULD COMBINE WITH FORCING ASSOCIATED WITH UPPER SYSTEM TO RESULT IN MEASURABLE SNOW ACROSS MOST OF THE REGION. UPSLOPE FLOW...ABUNDANT DEEP MOISTURE AND FAVORABLE TEMP PROFILE WILL COMBINE TO RESULT IN ENHANCED SNOWFALL IN THE FAVORED UPSLOPE REGION. PLAN TO LEAVE ADVISORIES UNCHANGED AS FORECASTED SNOW AMOUNTS SHOULD NOT REACH WARNING CRITERIA IN THE MOUNTAINS. PORTIONS OF NORTHERN WV AND SOUTHEAST OH...NEAR PKB...COULD SEE SNOWFALL AMOUNTS APPROACHING ADVISORY CRITERIA. AFTER COLLABORATING WITH NORTHERN NEIGHBORS...NO PLANS TO ADD THAT REGION TO THE ADVISORY AT THIS TIME. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY/... NOT MUCH CHANGE PLANNED FROM CURRENT FORECAST. STILL ON TRACK TO SEE UPSLOPE EVENT DURING THIS PERIOD. MODELS ARE NOW AGREEING ON LOCATION OF UPPER TROUGH AND TIMING OF IT SLIDING EAST. ALSO...-12C TO -18C RH IS ABOVE 90 PERCENT STARTING THIS PERIOD AND CONTINUING INTO EARLY TUESDAY. THIS IS OPTIMAL CRYSTAL GROWTH FOR SNOW. WITH WINDS IN THE LOW LEVELS OUT OF THE NORTHWEST...GOOD SNOW GROWTH...DECENT UPPER WAVE AND UPSLOPE...WILL INCREASE SNOW AMOUNT A BIT OVERNIGHT MONDAY. BY TUESDAY...DRIER AIR STARTS TO WORK ACROSS THE AREA AND SNOW WILL TAPER OFF. AS THE UPPER TROUGH MOVES EAST OF THE AREA...CONDITIONS WILL IMPROVE. DRY WEATHER WILL RETURN TUESDAY AFTERNOON THROUGH EARLY WEDNESDAY. THE NEXT CLIPPER SYSTEM WILL SWING SOUTHEAST FROM THE GREAT LAKES ON WEDNESDAY. COULD SEE SOME LIGHT SNOW SHOWERS TOWARD THE END OF THE PERIOD. FOR NOW...WILL LEAVE THE BULK OF WEDNESDAY DRY. H85 TEMPS WILL CONTINUE TO BE IN THE TEENS BELOW 0C MONDAY NIGHT THROUGH TUESDAY NIGHT. THIS WILL KEEP DAYTIME HIGHS IN THE TEENS TO AROUND 20F IN THE LOWLAND AND SINGLE DIGITS BELOW 0F IN THE MOUNTAINS. IF ANY CLEARING OCCURS OVERNIGHT TUESDAY IN THE MOUNTAINS...COLDER TEMPS WILL BE LIKELY THERE. WARM AIR ADVECTION RETURNS OVERNIGHT TUESDAY INTO WEDNESDAY. TEMPERATURES ON WEDNESDAY WILL RETURN TO THE 30S. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... ONE LAST UPPER LEVEL S/W TROF MOVES SE THROUGH THE AREA IN THE LARGER SCALE NW FLOW ALOFT RIGHT AT THE START OF THE PERIOD. UPSLOPE FLOW IN ITS WAKE SHOULD BRING LIGHT SNOW SHOWERS OR FLURRIES TO THE MOUNTAINS WED NT INTO THU MORNING. WITH HEIGHTS QUICKLY LIFTING THU...EXPECT THE AIR MASS IN THE WAKE OF THE FRONT TO NOT BE QUITE AS COLD AS ITS PREDECESSOR...AND THE UPSLOPE EVENT NO WHERE NEAR THE DURATION OR MAGNITUDE OF ITS PREDECESSOR. HIGH PRESSURE CROSSES THU NT...FOLLOWED BY SW FLOW ON ITS BACK SIDE FRI INTO THE WEEKEND. NEXT NORTHERN STREAM UPPER LEVEL S/W TROUGH DRIVES SURFACE COLD FRONT THROUGH THE AREA OVER THE WEEKEND...WITH MODEL DIFFERENCES ON TIMING. MOISTURE GETS DRAWN UP AHEAD OF THE FRONT INTO THE FORECAST AREA JUST AS THE FRONT APPROACHES SAT MORNING. AIR MASS BEHIND FRONT DOES NOT IT LEAST INITIALLY APPEAR TO BE AS COLD AS THE ONE CHARGING THROUGH EARLY THIS WEEK. UPPER LOW FORMS OVER THE SWRN CONUS EARLY IN THE WEEKEND IN RESPONSE TO RIDGING OFF THE W COAST. MODELS THEN START TO EJECT THIS LOW NEWD LATE IN THE WEEKEND WITH SOME TIMING DIFFERENCES IN TANDEM WITH SIMILAR DIFFERENCES IN THE NORTHERN STREAM. BLENDED IN MEX / HPC FOR TEMPERATURES...NO SIGNIFICANT CHANGES. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... LOW LEVEL MOISTURE PLUME EVIDENT ON WATER VAPOR IMAGERY STARTING TO APPROACH CWA. HAVE CIGS DROPPING TO MVFR W TO E OVER NEXT FEW HOURS WITH ARRIVAL OF THIS MOISTURE. WILL KEEP MVFR CIGS OVER LOWLAND COUNTIES THROUGH TODAY...HOWEVER VSBYS WILL DROP TO IFR OR LOWER IN SHSN TODAY AND TONIGHT. EXPECT VSBYS TO BOUNCE UP AND DOWN TODAY...THUS WILL INCLUDE TEMPO GROUPS TO COVER THIS. IN THE MOUNTAINS OF WV EXPECTING CIGS AND VSBYS TO BE IFR AND BOUNCING IN AND OUT OF LIFR IN INDIVIDUAL SHSN. IFR TO LIFR COULD PERSIST IN THE MOUNTAINS FOR QUITE SOME TIME...EVEN BEYOND THE SCOPE OF THIS ISSUANCE. EXPECTING A SLOW DECREASE IN THE WIND GUSTS WHICH ARE ALREADY EVIDENT IN THE OBSERVATIONS. SUSTAINED WINDS ARE NOT EXPECTED TO DROP BELOW 12KTS TO 15KTS THROUGH 00Z TUESDAY. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY... FORECAST CONFIDENCE:HIGH. ALTERNATE SCENARIOS: CIGS OVER THE LOWLANDS MAY DROP TO IFR WITH LOW LEVEL MOISTURE THROUGH TODAY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE MON 01/02/12 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12 CRW CONSISTENCY H H M M M L L L L L M M HTS CONSISTENCY H H M M M M L L L L M M BKW CONSISTENCY M M M M H H M M M M L L EKN CONSISTENCY L L L M M M M L L L L L PKB CONSISTENCY M M M M L L L L L L M M CKB CONSISTENCY M M L M M M M M M M M M AFTER 06Z TUESDAY... IFR IN SNOW SHOWERS POSSIBLE TUESDAY...CONDITIONS GRADUALLY IMPROVE INTO WEDNESDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO NOON EST TUESDAY FOR WVZ015-016-018-024>031-033-034. WINTER WEATHER ADVISORY UNTIL 4 PM EST TUESDAY FOR WVZ032- 035>040-046-047. OH...NONE. KY...NONE. VA...WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO NOON EST TUESDAY FOR VAZ003-004. && $$ SYNOPSIS...JB/TRM/TAX NEAR TERM...26/JSH/TAX SHORT TERM...JB LONG TERM...TRM AVIATION...26/TAX
AREA FORECAST DISCUSSION
NWS NORMAN OK
932 PM CST TUE JAN 3 2012 .UPDATE... BEST RADIATIONAL COOLING OVERNIGHT WILL BE ACROSS SOUTHEAST PART OF FA. WIND WILL DECREASE MORE AHEAD OF A FRONTAL BOUNDARY AND CLOUD COVER WILL ALSO HAVE LESS IMPACT. OVERALL FORECAST LOOKS IN GOOD SHAPE...BUT DID LOWER OVERNIGHT LOWS A FEW DECREASE ACROSS SOUTH CENTRAL AND SOUTHEAST OKLAHOMA. && .PREV DISCUSSION... /ISSUED 545 PM CST TUE JAN 3 2012/ AVIATION...VFR SKIES. TAF PERIODS WERE DETERMINED BY WINDS. FAIRLY CLEAR CUT AND WELL MODELED WIND SHIFT WILL OCCUR OVERNIGHT AS STEADY SOUTHERLY WINDS TURN LIGHT SOUTHWEST ALONG A TROUGH AXIS...AND THEN STRONGER FROM THE NORTH AFTER A FRONTAL PASSAGE. FORECAST FOLLOWS CLOSELY TO THE RUC AND NAM FOR TIMING OF BOUNDARIES AND RESULTING WIND DIRECTION. PREV DISCUSSION... /ISSUED 232 PM CST TUE JAN 3 2012/ DISCUSSION... A WEAK COLD FRONT WILL MOVE ACROSS THE FA TONIGHT INTO WEDNESDAY MORNING. HOWEVER... THE ONLY IMPACT WILL BE A WIND SHIFT WITH VERY LITTLE CHANGE IN TEMPERATURES. WARM TEMPS EXPECTED THURSDAY BEFORE ANOTHER COLD FRONT MOVES ACROSS THE AREA FRIDAY. AHEAD OF THE FRONT ON FRIDAY... ELEVATED FIRE WEATHER CONDITIONS MAY BECOME A CONCERN. HOWEVER... RIGHT NOW IT APPEARS THAT WILL NOT MEET RED FLAG CRITERIA FRIDAY. A COOLER AIRMASS WILL MOVE INTO THE REGION BEHIND THE FRONT DROPPING TEMPERATURES BACK DOWN TOWARDS NORMAL FOR THIS TIME OF YEAR OVER THE WEEKEND. MODELS CONTINUE TO DIFFER FROM RUN TO RUN AND WITH EACH OTHER AS TO AN UPPER SYSTEM THAT COULD MOVE ACROSS THE SOUTHERN PLAINS LATE THIS WEEKEND AND/OR EARLY NEXT WEEK. WITH THE UNCERTAINTIES DUE TO THE DIFFERING SOLUTIONS AND THE POSSIBILITY OF LIMITED MOISTURE IN THE REGION... WILL KEEP THE FORECAST DRY FOR NOW. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 32 57 32 65 / 0 0 0 0 HOBART OK 32 57 30 62 / 0 0 0 0 WICHITA FALLS TX 34 60 30 66 / 0 0 0 0 GAGE OK 28 62 27 70 / 0 0 0 0 PONCA CITY OK 29 54 30 62 / 0 0 0 0 DURANT OK 31 55 33 63 / 0 0 0 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$
AREA FORECAST DISCUSSION
NWS NORMAN OK
545 PM CST TUE JAN 3 2012 .AVIATION...VFR SKIES. TAF PERIODS WERE DETERMINED BY WINDS. FAIRLY CLEAR CUT AND WELL MODELED WIND SHIFT WILL OCCUR OVERNIGHT AS STEADY SOUTHERLY WINDS TURN LIGHT SOUTHWEST ALONG A TROUGH AXIS...AND THEN STRONGER FROM THE NORTH AFTER A FRONTAL PASSAGE. FORECAST FOLLOWS CLOSELY TO THE RUC AND NAM FOR TIMING OF BOUNDARIES AND RESULTING WIND DIRECTION. && .PREV DISCUSSION... /ISSUED 232 PM CST TUE JAN 3 2012/ DISCUSSION... A WEAK COLD FRONT WILL MOVE ACROSS THE FA TONIGHT INTO WEDNESDAY MORNING. HOWEVER... THE ONLY IMPACT WILL BE A WIND SHIFT WITH VERY LITTLE CHANGE IN TEMPERATURES. WARM TEMPS EXPECTED THURSDAY BEFORE ANOTHER COLD FRONT MOVES ACROSS THE AREA FRIDAY. AHEAD OF THE FRONT ON FRIDAY... ELEVATED FIRE WEATHER CONDITIONS MAY BECOME A CONCERN. HOWEVER... RIGHT NOW IT APPEARS THAT WILL NOT MEET RED FLAG CRITERIA FRIDAY. A COOLER AIRMASS WILL MOVE INTO THE REGION BEHIND THE FRONT DROPPING TEMPERATURES BACK DOWN TOWARDS NORMAL FOR THIS TIME OF YEAR OVER THE WEEKEND. MODELS CONTINUE TO DIFFER FROM RUN TO RUN AND WITH EACH OTHER AS TO AN UPPER SYSTEM THAT COULD MOVE ACROSS THE SOUTHERN PLAINS LATE THIS WEEKEND AND/OR EARLY NEXT WEEK. WITH THE UNCERTAINTIES DUE TO THE DIFFERING SOLUTIONS AND THE POSSIBILITY OF LIMITED MOISTURE IN THE REGION... WILL KEEP THE FORECAST DRY FOR NOW. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 32 57 32 65 / 0 0 0 0 HOBART OK 32 57 30 62 / 0 0 0 0 WICHITA FALLS TX 34 60 30 66 / 0 0 0 0 GAGE OK 28 62 27 70 / 0 0 0 0 PONCA CITY OK 29 54 30 62 / 0 0 0 0 DURANT OK 35 55 33 63 / 0 0 0 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 06/22/22
AREA FORECAST DISCUSSION
NWS SPOKANE WA
244 PM PST Mon Jan 2 2012 .SYNOPSIS...A weak cold front will pass through the Inland Northwest tonight bringing a good chance of light rain and snow...to most locations north of I90. After this front passes through the weather will turn drier for most locations through Wednesday. Through the end of the workweek and into the weekend...a series of relatively weak weather disturbances will deliver a decent chance of valley rain and light mountain snow accumulations every 24 to 36 hours. && .DISCUSSION... Tonight...Compact upper level low and associated occluded front will provide to focus for the weather tonight across the Inland Northwest. As of 2pm...the upper level low was just off the Olympic Peninsula with the frontal occlusion extending south- southeast toward the Portland area. The low was being picked up fairly well by the short-range models...however the NAM solution was a bit too far to the south whereas the ECMWF and RUC were faring much better. Both these solutions take the core of the upper level cold pool and shortwave trough into extreme southeast BC by 06z and into southern Saskatchewan by 12z. The occluded front will track along with the upper level and spread precipitation across the northern half of the forecast area. We expect the Cascades will sap some of the moisture as it tracks into the western Columbia Basin early this evening but it will regain its continuity as it moves into northeast Washington and north Idaho late this evening. Precipitation chances look very good as strong isentropic ascent develops north of a Coulee Dam to Sandpoint line. This lifting will also tap into the deep instability through the dendritic layer associated with the cold core upper level shortwave trough. The weather type over these areas will undoubtedly fall as snow with wet-bulb temperatures well below zero through the entire lower atmosphere. Most of the northern valleys in Washington into north Idaho will see snowfall amounts ranging from 0.5-1.5 inches with 1-3" totals probable across the Methow and upper Wenatchee Valleys. Where the forecast becomes more dicey is over the northern Columbia Basin from Wenatchee to Spokane. Precipitation in this region is far from certain and anything which does fall should be fairly light. The big question is what will it fall as. We suspect closer to the Cascades it will fall as all snow...but over Lincoln and Spokane County...model consistency is poor. Some solutions suggest a snow level near 4000 feet while others have it near the ground. Based on the latest surface observations we will lean toward the lower numbers...but even so we don`t expect to see much in the way of accumulation. Precipitation chances over SE Washington into the central Panhandle look quite small. Precipitation chances will gradually taper off over most areas overnight as the upper level trough and occluded front track well east of the region. The exception will occur near the Cascade crest and Idaho Panhandle mountains where moist and somewhat unstable flow will continue to produce some residual showers. fx Tuesday through Thursday...The progressive weather pattern will continue across the region with a mainly dry day expected Tuesday before the next weather system in the conga line brings rain and mountain snow to the Inland Northwest by mid-week. As warm air advection starts to take place in the mid levels, there may be pockets of freezing rain in the northern Cascade valleys Tuesday night but the more likely scenario would be wet snow. By Wednesday the advancing warm front will tap into a subtropical fetch of moisture with twice the normal precipitable water levels. Warm air advection will strengthen Wednesday, pushing snow levels well above all valley floors during the day. Decent isentropic lift into the northeast mountains and Idaho Panhandle Wednesday night will combine with orographic ascent to enhance precipitation across the northeast zones. The cold front will sweep through the forecast area Thursday. Models continue to show weaker surface pressure gradients than previous solutions with this frontal zone. Conditions should be breezy to windy with the cold frontal passage. We should see some strong gusts but they will probably remain just below advisory criteria. Storm total precipitation is in the range of 1 to 2 tenths in the lower valleys with a quarter inch to 4 tenths for the valleys across the northern half of the forecast area. The mountains (other than the Blues) could see a half to three quarters of an inch of liquid from the mid week system. The high mountains could see some significant snowfall during this event. The only area of concern will be the east slope Cascade valleys like the Methow where cold air will be difficult to scrub out. They could see a few inches of accumulation Tuesday night into Wednesday before snow levels rise. By the time colder air moves in behind the cold front Thursday, QPF will be much lighter and in the form of scattered showers, with only very light accumulations expected in the valleys, if any at all. Temperatures will be on a warming trend Tuesday and Wednesday, then cool behind the cold front Thursday. /Kelch Thursday night through Monday: Upper level ridge starts to push inland Thursday night as the cold front exits north Idaho. A drying trend is expected Thur night and Friday as the ridge shifts over the inland northwest. The exception to this is across the mountains where a light shower is possible. The flow remains fairly progressive with a weak feature moving through Friday night in northwest flow ahead of another ridge. Right now models aren`t showing anything impressive with this wave, it looks to impact mostly extreme eastern WA and north ID with no exciting amounts of snowfall. From Saturday afternoon through Monday it looks like the ridge dominates with all weather systems going north into British Columbia. By Monday I did trend a bit toward climatology given some uncertainty with the GFS hinting at a trough possibly moving into the area. The big change in the extended forecast was to start trending chance of precipitation down. Took mention of showers out of the valleys and low lying areas and kept slight chance to chance in the mountains. Temperatures are expected to be around average for this time of the year. /Nisbet && .AVIATION... 00z TAFs...Tuesday morning portion of the forecast will have increasing low level clouds throughout the region. Precip type will provide the main challenge as temps will be precariously close to freezing at the onset of the event. At EAT...there is no guarantee that any precip will fall...but if it does...there are better chances of rain than snow. KGEG is expected to receive mainly rain with a slight chance of snow mix. KSFF will get rain. The amounts of precip will be light. Late in the TAF period the most sites except for KPUW...KLWS...KMWH can expect to see IFR to MVFR due to ceilings. /JDC && .PRELIMINARY POINT TEMPS/POPS... Spokane 28 39 31 44 34 40 / 40 0 10 20 40 30 Coeur d`Alene 30 42 31 46 32 43 / 50 10 10 20 40 60 Pullman 33 46 34 49 35 43 / 20 0 0 10 30 50 Lewiston 34 48 37 51 39 49 / 10 0 0 0 30 40 Colville 26 40 31 42 31 40 / 70 20 20 30 60 60 Sandpoint 30 39 32 43 33 38 / 60 20 20 30 60 70 Kellogg 30 40 31 44 32 40 / 60 10 20 20 50 70 Moses Lake 26 42 30 46 34 43 / 10 0 10 10 40 10 Wenatchee 28 40 30 40 33 39 / 20 10 10 20 50 10 Omak 23 38 30 39 31 38 / 40 10 20 30 50 20 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
915 PM CST TUE JAN 3 2012 .UPDATE... NO CHANGES TO GOING FORECAST. SOUTH WINDS AND CLOUD COVER HAVE HAD EXPECTED AFFECT OF HOLDING TEMPERATURES LEVEL THIS EVENING...WITH AN EXPECTED COOL DOWN AFTER SURFACE TROUGH PASSAGE AND CLEARING SKIES. && .AVIATION/06Z TAFS/... BASED ON LATEST RUC SOUNDINGS AND TIMING OF 850 MB AND 700 MB TROUGHS...DIFFERENTIAL BETWEEN SURFACE WINDS AND 2000 FT WINDS SHOULD FALL BELOW 30 KNOTS BY ISSUANCE TIME SO PLAN IS TO DROP LOW-LEVEL WIND SHEAR FROM 06Z TAFS...THOUGH WILL WATCH BOTH KMKE AND KENW PRIOR TO ISSUANCE TO SEE IF IT WILL LINGER AN HOUR OR TWO INTO THE NEW FORECAST PERIOD. LATEST NAM-BASED MOS GUIDANCE HAS DROPPED THE POST-SURFACE TROUGH MVFR CIGS BETWEEN 12Z AND 18Z WEDNESDAY...SUPPORTED BY LACK OF STRATUS ON FOG PRODUCT AND IR SATELLITE IMAGERY UPSTREAM OVER THE EASTERN DAKOTAS/WESTERN MN SO VFR CONDITIONS EXPECTED THROUGH THE PERIOD. WILL NEED TO WATCH IF INCREASE IN BOUNDARY LAYER MOISTURE FROM DEW POINT ADVECTION AND MELTING SNOW IS SUFFICIENT FOR FOG OVERNIGHT WEDNESDAY NIGHT && .MARINE... WHILE MOST SHORE OBS ARE NO LONGER GUSTING TO SMALL CRAFT CRITERIA AS WINDS HAVE SHIFTED FROM SOUTH TO SOUTH-SOUTHWEST...THE SHEBOYGAN C-MAN AND SHIP OBS IN OR NEAR THE NEARSHORE ZONES FROM CHICAGO NORTH TO SHEBOYGAN ARE REPORTING SMALL CRAFT VALUES WITH SOME TOWARD THE HIGHER END...SHOWING THE BETTER OVER-WATER MIXING UP TO 30-35 KNOT 1000 FT WINDS. TIMING CURRENT PROGRESS OF TROUGH AND BAGGY SURFACE GRADIENT FOLLOWS FORECAST OF BRINGING LOWER WINDS TO THE WESTERN LAKE MICHIGAN SHORE BETWEEN 1 AM AND 2 AM. WHILE WAVES ARE AT OR BELOW CRITERIA...WILL STILL KEEP CURRENT END TIME OF 4 AM TO ASSURE GUSTS ARE BELOW CRITERIA AND HIGHER END WAVES BELOW 4 FEET. && .PREV DISCUSSION... /ISSUED 325 PM CST TUE JAN 3 2012/ VERY SHORT TERM...TONIGHT AND WEDNESDAY. DECENT SHORTWAVE TO ROLL THROUGH LATER TONIGHT. A RESPECTABLE AMOUNT OF LIFT IN MODEL SOUNDINGS...BUT VERY LIMITED MOISTURE BELOW 10-15 KFT. NOT REALLY SEEING ANY PRECIP UPSTREAM EITHER...SO DECIDED TO REMOVE FLURRIES IN THE NORTH FOR TONIGHT. WILL HAVE MID AND HIGH LEVEL CLOUDS ROLL THROUGH...WITH CLEARING SKIES LIKELY BY MORNING. TEMPS WILL LIKELY NOT FALL THAT FAR TONIGHT...WITH THE CLOUDS STICKING AROUND MUCH OF THE NIGHT. WINDS WILL INCREASE LATE AFTERNOON INTO THE EVENING...STAYING UP THROUGH AT LEAST MIDNIGHT. THIS WILL ALSO KEEP TEMPS FROM GETTING THAT COLD. MORE MID AND HIGH LEVEL CLOUDS TO MOVE IN FROM THE NORTHWEST LATE MORNING OR EARLY AFTERNOON WEDNESDAY...BUT OTHERWISE QUIET WEATHER EXPECTED. TEMPS WILL CONTINUE TO WARM...WITH LOW TO MID 30S EXPECTED. SNOW PACK WILL LIKELY KEEP TEMPS A BIT COOLER ACROSS THE NORTHEAST HALF OF THE FORECAST AREA. TRENDED TOWARD MILDER ECMWF AND CANADIAN THOUGH...AS NAM AND GFS SEEM TOO COOL GIVEN CURRENT 2M TEMPS AND OBSERVATIONS. SHORT TERM...WEDNESDAY NIGHT THROUGH FRIDAY. LACK OF A SIGNIFICANT SNOWPACK TO THE SOUTH OR WEST TO HOLD DOWN DAYTIME TEMPS THE NEXT FEW DAYS...SO NOTICEABLE WARMUP STILL ON TRACK FOR THU AND FRI. ALSO WITH LACK OF SNOWPACK TO MELT...NO ADDITION OF ADDED LOW LEVEL MOISTURE TO CONTRIBUTE TO STRATUS OR FOG POTENTIAL FROM THE SOUTH. IN FACT...DRY AIR WITH DEWPTS LESS THAN 20 EXTENDS ALL THE WAY TO THE GULF SOUTH OF WI...WITH SOME UPSTREAM 20S IN THE PLAINS. FOR THIS PERIOD...MID LEVEL STEERING WINDS CONTINUE TO BACK TO THE WEST AS LONG WAVE TROUGH OVER THE NORTHERN PACIFIC WEAKENS AND KNOCKS DOWN UPSTREAM RIDGING OVER NORTH CENTRAL CONUS. HENCE INCREASING WESTERLY WINDS BEGIN TO PULL IN MUCH WARMER LOW LEVEL AIR ON THU AND FRI. 85H TEMPS WILL WARM 20C FROM MID-DAY TODAY TO MID-DAY THURSDAY. INITIAL SURGE OF WARM AIR WILL LIKELY BRING ANOTHER ROUND OF MID-HIGH LEVEL CLOUDS TO THE AREA WED NIGHT. DO NOT MIX UP TO 85H...BUT SUNSHINE AND DRY ATMOSPHERE WL ENCOURAGE WARMER TEMPS. STRONGEST FORCING TO THE NORTH WHILE LOWER LEVELS REMAIN DRIER TO THE SOUTH WED NGT. WEAK SURFACE FRONT SLIDES SOUTH ACROSS SOUTHERN WI THU NGT AND FRI...HOWEVER CONVERGENCE WEAK AND LOW LEVELS REMAIN DRIER. SO WL CONTINUE DRY FORECAST FOR THIS PERIOD...BUT GO WITH MORE P/CLDY WORDING. LOW LEVEL TEMPS REMAIN MILD DESPITE WNW SFC WINDS. THINKING MUCH OF THE LIGHT SNOWPACK TO THE NORTH WILL BE GONE BY FRIDAY...SO EXPECTING ANOTHER MILD...ABOVE NORMAL DAY...WITH HIGH TEMPS REACHING THE LOWER 40S. LONG TERM...FRIDAY NIGHT THROUGH TUESDAY. BENIGN WEATHER LOOKS TO CONTINUE FOR THE BULK OF THIS FORECAST PERIOD...WITH ABOVE NORMAL TEMPERATURES FOR MOST OF THE PERIOD. EXTENDED GUIDANCE IN REASONABLE AGREEMENT FOR THE PROLONGED STRETCH OF QUIET WEATHER. MAYBE A PERIOD OF COLD AIR STRATOCUMULUS FRIDAY NIGHT AS LOW LEVEL WINDS VEER TO THE NORTHWEST ALLOWING COOLER AIR TO RETURN TO SRN WI. FORCING WL BE WEAK...AND MOISTURE TO REMAIN SPARSE ABV 5K FEET...SO AT THIS POINT WL CONTINUE DRY FORECAST FOR START OF EXTENDED PERIOD. WEAK LOW PRESSURE PASSING EWD THROUGH THE NRN GTLAKES FRI NIGHT WL LEAVE BEHIND A WEAK BAROCLINIC ZONE ON SAT AND SAT NGT. HOWEVER THIS WEAK FRONT MAKES LITTLE PROGRESS SWD...PERHAPS DUE TO LINGERING WARMER LAKE WATERS IN THE SRN GTLAKES. THIS BOUNDARY WEAKENS AS A HIGH PRESSURE RIDGE THEN PASSES THRU THE WRN GTLAKES ON SUN. TEMPERATURES WILL BRIEFLY LOWER CLOSER TO SEASONAL NORMALS ON SAT AND SUN. INCREASING WEST WINDS ON THE BACKSIDE OF THE HIGH PRESSURE AREA WILL ALLOW WARMER AIR TO RETURN ON MONDAY AND TUESDAY...WITH CLIMBING BACK ABV NORMAL. DEEPER MOISTURE REMAINS CUTOFF TO THE SOUTH...HOWEVER STRONG SURGE OF WARM AIR ADVECTION MAY RESULT IN BRIEF PERIOD OF LIGHT PRECIPITATION SUN NGT OR MON OVER SRN WI. BEST FORCING AND THREAT OF PRECIPITATION WL BE TO THE NORTH. DUE TO UNCERTAINTY...WL CONTINUE DRY WORDING FOR NOW. GFS 5 DAY 5H MEANS DOES SHOW HIGHER AMPLITUDE TROFFING EXPCD TO DEVELOP IN THE WRN CONUS BY THE MIDDLE OF NEXT WEEK...WITH LARGE POSITIVE ANOMOLY OF OVER 300METERS OVER THE NRN PAC INTO SRN AK. HENCE LOOK FOR MORE UNSETTLED WEATHER TO RETURN TOWARD THE LATTER HALF OF NEXT WEEK. AVIATION /00Z TAFS/...MID AND HIGH LEVEL CLOUDS EXPECTED THROUGH TONIGHT AS SHORTWAVE ROLLS THROUGH...WITH BRIEF CLEARING BY MORNING. MOISTURE VERY LACKING IN THE LOWER LEVELS...SO NOT EXPECTING ANY PRECIP WITH THE WAVE. ANOTHER QUIET DAY EXPECTED WEDNESDAY...WITH ONLY MORE MID AND HIGH LEVEL CLOUDS MOVING IN LATE MORNING OR EARLY AFTERNOON. MARINE...AN APPROACHING TROUGH WILL TIGHTEN THE PRESSURE GRADIENT ACROSS SOUTHERN LAKE MICHIGAN LATE THIS AFTERNOON AND INTO THE EVENING. SOUTH TO SOUTHWEST WINDS WILL INCREASE...WITH GUSTS TO 25 KNOTS LIKELY DURING THE EVENING AND INTO THE OVERNIGHT HOURS...PARTICULARLY TOWARD OPEN WATERS. HAVE THUS DECIDED TO ISSUE A SMALL CRAFT ADVISORY FROM 00Z THIS EVENING UNTIL 10Z LATE TONIGHT. THOUGH WAVES MAY APPROACH 4 FEET...ESPECIALLY ACROSS THE NORTH TOWARD OPEN WATERS...WAVE ARE GENERALLY EXPECTED TO REMAIN BELOW 4 FEET. CONFIDENCE... TONIGHT AND WEDNESDAY...HIGH. WEDNESDAY NIGHT THROUGH FRIDAY...MEDIUM TO HIGH. FRIDAY NIGHT THROUGH TUESDAY...MEDIUM. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY UNTIL 4 AM CST WEDNESDAY FOR LMZ643>646. && $$ UPDATE...REM TONIGHT/WEDNESDAY AND AVIATION/MARINE...DDV WEDNESDAY NIGHT THROUGH TUESDAY...MBK
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
522 PM CST TUE JAN 3 2012 UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE .SHORT TERM...TONIGHT AND WEDNESDAY. LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE HIGH PRESSURE SHIFTING EAST OVER THE CENTRAL GREAT LAKES THIS AFTERNOON...IN RESPONSE TO MID-LEVEL HEIGHT FALLS OCCURRING OVER THE NORTHERN PLAINS AHEAD OF A SHORTWAVE TROUGH. AHEAD OF THIS TROUGH...MID AND HIGH CLOUDS ARE ON THE INCREASE ACROSS THE REGION. A WARM FRONT LIES FURTHER UPSTREAM ACROSS THE PLAINS BUT THE RAOB NETWORK SHOW AMPLE DRY AIR IN THE MID-LEVELS AND A LACK OF PRECIP. AS THE SHORTWAVE MOVES ACROSS THE REGION TONIGHT...CONCERNS FOCUS ON SMALL POP CHANCES AND TEMPS. TONIGHT...SHORTWAVE TROUGH OVER THE NORTHERN PLAINS WILL SLIDE SOUTHEAST AND BECOME ELONGATED. COMBINED WITH LIFT OVER A H850 WARM FRONT...THE WAVE HAS SOME DECENT FORCING WITH IT. BUT SOUNDINGS UPSTREAM REMAIN PRETTY DRY IN THE MID-LEVELS...AND CANNOT FIND ANY PRECIP REPORTED IN THE OBS OVER SOUTHERN MANITOBA AND SASKATCHEWAN. AS A RESULT...WILL REMOVE THE LIGHT SNOW SHOWER AND FLURRY MENTION. WINDS WILL BE STRENGTHENING OUT OF THE SOUTHWEST AHEAD OF THE SHORTWAVE AND MAY FIND IT DIFFICULT FOR WINDS TO DECOUPLE. WITH THE BKN MID AND HIGH CLOUD COVER...TEMPS WILL BE SIGNIFICANTLY WARMER THAN LAST NITE. LOWS RANGING THROUGH THE TEENS. WEDNESDAY...POTENT 150KT JET STREAK WILL DIVE SOUTHEAST OVER THE WESTERN GREAT LAKES IN THE AFTERNOON. LEFT FRONT QUAD OF THE JET WILL PASS TO THE EAST OF THE REGION...KEEPING ANY UPPER DIVERGENCE FROM CREATING LIGHT PRECIP. WILL STILL SEE INCREASING MID AND HIGH CLOUDS (ABOVE 9KFT OR SO) AFTER A PERIOD OF MOSTLY CLEAR TO PARTLY CLOUDY CONDITIONS IN THE MORNING. TEMPS WILL CONTINUE TO REBOUND TO THE UPPER 20S AND LOWER 30S. .LONG TERM...WEDNESDAY NIGHT THROUGH NEXT TUESDAY. OVERALL MAINLY A QUIET AND RELATIVELY MILD PATTERN DURING THIS PERIOD. UPPER HEIGHTS BUILD WEDNESDAY NIGHT INTO THURSDAY AS A WEAK SURFACE HIGH RIDGE SLIDES OVER. UPPER FLOW BREAKS DOWN BRIEFLY AS A BROAD UPPER TROUGH WORKS OVER THE NORTHERN US REGION. A PERIOD OF WARM AIR ADVECTION AHEAD OF THIS UPPER TROUGH WILL BRING A NEAR STEADY TEMPERATURE TREND TO THE AREA THURSDAY NIGHT. AN ASSOCIATED SURFACE LOW PRESSURE SYSTEM TRACKING OVER THE NORTHERN GREAT LAKES REGION WILL THEN SLIDE A WEAK COLD FRONT OVER THE STATE ON FRIDAY. ANY PCPN WILL BE MINIMAL AND CONFINED WELL NORTH CLOSER TO THE SYSTEM ALONG WITH A PERIOD OF CAA OVER LAKE SUPERIOR. WHILE SURFACE RIDGING SETTLES BACK INTO THE AREA FOR THE WEEKEND WITH THE WESTERN STATES UPPER RIDGE BUILDING...A CONTINUED PARADE OF WEAK MID LEVEL SUBTLE SHORT WAVES ARE PROGGED TO DROP OVER THE AREA FOR THE WEEKEND. AS HAS BEEN THE CASE LATELY...LITTLE MOISTURE AVAILABLE WITH THESE PACIFIC ORIGIN SYSTEMS. MEDIUM RANGE RUNS FLATTEN THE WESTERN RIDGE FOR THE START OF THE NEW WEEK WITH BUILDING UPPER HEIGHTS FOR THE FORECAST AREA. ANOTHER WARMING TREND IS ANTICIPATED WITH THE RETURN SOUTHWEST TO WEST FLOW AS THE MAIN LOW PRESSURE SYSTEM PASSES WELL NORTH OF THE GREAT LAKES REGION. WILL GO ABOVE GUIDANCE NUMBERS THURSDAY NIGHT AS WELL AS NEXT WEEK DUE TO THE WARM AIR ADVECTION. THE AMOUNT OF WARM UP WILL BE TRICKY DUE TO THE LACK OF SNOW COVER WEST TO SOUTHWEST OF THE AREA...BUT STILL NEED TO FACTOR IN A COLD GROUND/INVERSION AND LOW SUN ANGLE...NOT TO MENTION SKY CONDITION. && .AVIATION...FOR 00Z TAF ISSUANCE. FAIRLY QUIET AS JUST HIGH AND SOME MIDDLE CLDS EXPECTED TO WORK ACRS THE RGN AS FRONTAL SYSTEM MOVES ACRS THE AREA. THE ONLY ITEM OF NOTE IS LLWS...WHICH WL BE A CONCERN AT THE START OF THE TAFS BUT DECR DURING THE NGT AS THE CORE OF THE STRONGEST WINDS ABV THE SFC SHIFTS E. SKOWRONSKI && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
515 PM CST TUE JAN 3 2012 .SHORT TERM...TONIGHT THROUGH FRIDAY 237 PM CST TUE JAN 3 2012 MAIN FORECAST CONCERNS ARE ON ANY CHANCES FOR PRECIPITATION TONIGHT...THEN THE ABOVE NORMAL TEMPERATURE PATTERN THROUGH FRIDAY. CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED RIDGING PRETTY MUCH DOMINATING THE WESTERN TWO THIRDS OF THE U.S. INTO SOUTHERN CANADA...EXCLUDING A POSITIVELY TILTED SHORTWAVE TROUGH ENTERING THE WESTERN DAKOTAS...WHILE DEEP TROUGHING EXISTED ALONG THE EAST COAST. STRONG WARM ADVECTION HAS BEEN OCCURRING AHEAD OF THE WESTERN DAKOTAS SHORTWAVE...NOTED BY 850MB TEMPS THAT ROSE NEARLY 15C AT ABR AND 8C AT MPX BETWEEN THE 00Z AND 12Z SOUNDINGS. BOTH SOUNDINGS DEPICT A STRONG INVERSION...ESPECIALLY AT ABR...AND IS TO BE EXPECTED THIS TIME OF YEAR WITH SHALLOW COLD AIR MASSES MORE DOMINANT. DAYTIME MIXING THROUGH HIGH CLOUDS AHEAD OF THE SHORTWAVE TROUGH HAS ALLOWED SURFACE TEMPERATURES TO CLIMB INTO THE 20S OVER THE FORECAST AREA...AND INTO THE 30S OVER SOUTHWEST MN INTO WESTERN IOWA. AIR ACROSS THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI RIVER VALLEY WAS QUITE DRY AS WELL...WITH DEWPOINT DEPRESSIONS OFF THE 12Z GRB...MPX AND ABR SOUNDINGS OF 10C OR MORE FROM 950-650MB. AT THE SURFACE...A WARM FRONT WAS LOCATED ALONG THE DAKOTAS/MN BORDER...WITH BREEZY SOUTH WINDS AHEAD OF IT INTO THE FORECAST AREA. BEHIND THE FRONT...READINGS ARE IN THE 40S AND 50S OVER THE DAKOTAS. TONIGHT AND WEDNESDAY...MODELS PROG THE POSITIVELY TILTED SHORTWAVE TROUGH OVER THE WESTERN DAKOTAS TO MOVE SOUTHEAST ACROSS THE FORECAST AREA BETWEEN 06-12Z TONIGHT. IN ITS WAKE...40-70 METER HEIGHT RISES ARE EXPECTED FOR WEDNESDAY AT 500MB WHILE ANOTHER WEAK SHORTWAVE DROPS SOUTHEAST INTO UPPER MICHIGAN. MAIN CONCERN IS WHETHER OR NOT THE SHORTWAVE TROUGH CAN PRODUCE PRECIPITATION TONIGHT. CERTAINLY THERE ARE DECENT 500MB HEIGHT FALLS...60-90 METERS...INDICATIVE OF THE DYNAMIC FORCING. HOWEVER...ISENTROPIC LIFT PLOTS ON 285K-300K SURFACES SHOW LITTLE OR NO LIFT...AS WELL AS PLENTY OF DRY AIR BETWEEN 850-600MB. THEREFORE...NOT EXPECTING ANY PRECIPITATION WITH THE TROUGH. AFTER THIS...THE ONLY CONCERN IS CLOUD COVER. THERE MAY BE SOME LOW CLOUDS IN THE WAKE OF THE TROUGH...BUT MOST OF THESE ARE EXPECTED TO STAY NORTH AND EAST OF THE AREA. ADDITIONAL MID/HIGH CLOUD COVER LOOKS TO COME IN WEDNESDAY AFTERNOON WITH THE NEXT SHORTWAVE...BUT MOST OF THESE CLOUDS SHOULD STAY ALONG OR NORTHEAST OF I-94. REGARDING TEMPERATURES...LOWS TONIGHT WILL END UP MUCH WARMER THAN LAST NIGHT...AIDED BY CLOUD COVER AND THE PASSAGE OF THE WARM FRONT. PREVIOUS FORECAST LOWS SEEM REASONABLE WHICH ONLY SHOW ABOUT A 5 DEGREE TEMPERATURE DROP FROM CURRENT READINGS. GIVEN A WARMER START FOR TOMORROW AND 925MB TEMPS CLIMBING TO -2C TO +1C...HIGHS SHOULD EASILY REACH THE 30S IN MOST LOCATIONS. A FEW LOCATIONS IN NORTHEAST IOWA COULD EVEN REACH 40. WEDNESDAY NIGHT THROUGH FRIDAY...UPPER LEVEL TROUGHING...CURRENTLY SEEN ON WATER VAPOR OVER THE NORTHEAST PACIFIC...IS PROGGED TO MOSTLY EJECT OUT AND DROP DOWN INTO THE NORTHERN PLAINS AND SOUTH CENTRAL CANADA COME FRIDAY IN A POSITIVELY TILTED FORM. AS THE TROUGH HEADS EAST...A SURGE OF PACIFIC AIR ADVECTS EAST WITH IT INTO THE FORECAST AREA...WARMED UP EVEN MORE IN RESPONSE TO DOWNSLOPING OFF THE ROCKIES. 850MB TEMPS CLIMB FROM 0-2C AT 00Z THURSDAY TO AS MUCH AS 8-12C AT 00Z FRIDAY. SOME COOL DOWN IN 850MB TEMPS IS FORECAST FOR FRIDAY WITH READINGS DROPPING FROM 6-10C AT 12Z FRIDAY TO -2 TO +2C BY 00Z SATURDAY...ALL IN RESPONSE TO THE APPROACHING TROUGH. ALTHOUGH A LOT OF THIS WARMING IS TAKING PLACE ALOFT...AGAIN AS TO BE EXPECTED THIS TIME OF YEAR WITH A LOWER SUN ANGLE AND SHORTER DAY LENGTH...THE LACK OF SNOW COVER WILL HELP WITH MIXING. HOW WARM WE ACTUALLY GET IS THE BIG QUESTION. FIRST OFF...THIS TIME PERIOD WILL END UP DRY DUE TO THE SERIOUS LACK OF MOISTURE BELOW 10000 FT AS SEEN ON MODEL SOUNDINGS. NOW REGARDING CLOUD COVER. A STREAM OF MID-HIGH CLOUDS OVER WISCONSIN LATE WEDNESDAY LOOKS TO PUSH SLOWLY EAST THROUGH THURSDAY...IN RESPONSE TO THE BUILDING HEIGHTS ALOFT. ANOTHER SURGE OF MID/HIGH CLOUDS LOOKS TO CROSS THE ENTIRE FORECAST AREA THURSDAY NIGHT...IN THE WESTERLY FLOW AHEAD OF THE SHORTWAVE TROUGH...BUT THESE APPEAR TO SCATTER OUT AND DROP SOUTH FOR FRIDAY. THEREFORE...BOTH THURSDAY AND FRIDAY SHOULD END UP SUNNY/MOSTLY SUNNY. WINDS ARE FORECAST OUT OF GOOD DIRECTIONS FOR WARMING...SOUTHWEST ON THURSDAY AND WEST TO NORTHWEST ON FRIDAY... THOUGH THE SPEEDS ARE 5 TO 10 KT AT BEST. PAST VERIFICATION OF ABOVE NORMAL TEMPERATURE EVENTS SHOWS THAT THE ECMWF TENDS TO DO THE BEST...SO THIS FORECAST LEANS CLOSE TO THE ECMWF GUIDANCE... PARTICULARLY FOR HIGHS. .LONG TERM...FRIDAY NIGHT THROUGH TUESDAY 237 PM CST TUE JAN 3 2012 03.12Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES REMAIN IN VERY GOOD AGREEMENT WITH THE HANDLING OF THE UPPER AIR AND SURFACE PATTERNS THROUGHOUT MUCH OF THE CONUS DURING THE LONG TERM PERIOD. THIS LEADS TO...AT LEAST AT THE MOMENT...ABOVE AVERAGE CONFIDENCE. GENERAL PATTERN SHOWS TROUGHING OVER THE FORECAST AREA SOUTHWESTWARD INTO THE SOUTHWEST U.S. FOR THE WEEKEND. THIS TROUGHING IS CREATED BY THE TROUGH APPROACHING THE AREA ON FRIDAY...A POTENT SHORTWAVE DROPPING SOUTH THROUGH THE ROCKIES...AND THEN ON SUNDAY A SHORTWAVE DROPPING DOWN TOWARD THE AREA. THIS LAST SHORTWAVE COMES DOWN A BUILDING RIDGE OVER THE WESTERN U.S. INTO SOUTHWEST CANADA. WITH THE UPPER TROUGHING OVER THE FORECAST AREA FRIDAY NIGHT THROUGH SUNDAY... COOLER TEMPERATURES CAN BE EXPECTED. 850MB TEMPS FALL TO -6 TO -10C AT 18Z SATURDAY WITH ONLY A SLIGHT WARM UP TO -5 TO -8C AT 18Z SUNDAY. A BLEND OF GUIDANCE SEEMS REASONABLE FOR TEMPERATURES AT THIS TIME. DESPITE THE UPPER TROUGHING MOVING ACROSS...THERE IS VERY LITTLE MOISTURE TO WORK WITH...THEREFORE NO PRECIPITATION IS FORECAST FOR THE WEEKEND AT THIS TIME. FOR MONDAY INTO TUESDAY...A MORE POTENT UPPER TROUGH LOOKS TO MOVE OUT OF THE NORTHEAST PACIFIC INTO SOUTHWEST CANADA...WHICH MAY START DIGGING INTO THE NORTHERN PLAINS LATE TUESDAY. THIS UPPER TROUGH HELPS SHUNT THE BUILDING RIDGING OUT WEST TOWARDS THE FORECAST AREA...BRINGING WITH IT YET ANOTHER SURGE OF PACIFIC AIR. 850MB TEMPS CLIMB RAPIDLY TO AT LEAST 0 TO +6C BY 00Z TUESDAY...IF NOT HIGHER. BY 12Z TUESDAY...THEY ARE SOLIDLY UP TO 6-8C. SOME COOLING COULD OCCUR LATE TUESDAY...DEPENDING ON HOW FAST THAT UPPER TROUGH APPROACHES. IN ANY EVENT...BOTH MONDAY AND TUESDAY LOOK ABOVE TO WELL ABOVE NORMAL AGAIN...ESPECIALLY GIVEN THE LACK OF SNOW COVER. STAYED CLOSER TO THE WARM END OF GUIDANCE FOR HIGHS. PRECIPITATION CHANCES STILL ARE NIL WITH A LACK OF MOISTURE...AND FORCING IN THIS CASE. LOOKING AHEAD...A COLD SHOT OF AIR...SIMILAR TO THE ONE JUST EXPERIENCED YESTERDAY...APPEARS IN THE OFFERING FOR THE MIDDLE AND END OF NEXT WEEK. THIS IS DUE TO THE TROUGHING APPROACHING THE AREA ON TUESDAY DIGGING DOWN TOWARDS THE OHIO VALLEY. RIGHT NOW ANY PRECIPITATION ASSOCIATED WITH THE TROUGH APPEARS TO BE LIGHT...BUT THIS IS STILL 8-10 DAYS OUT. && .AVIATION... 515 PM CST TUE JAN 3 2012 SFC FRONT WILL SLIDE WEST-EAST ACROSS THE REGION TONIGHT...AROUND 07Z AT KRST AND 09Z AT KLSE. LITTLE LOW LEVEL SATURATION FOR THE FRONT TO WORK ON...SO ONLY SOME HIGH VFR CLOUDS AS THE FRONT MOVES THROUGH. VFR CONDITIONS WILL PERSIST WED WITH WEST-NORTHWEST WINDS. && .ARX WATCHES/WARNINGS/ADVISORIES... 237 PM CST TUE JAN 3 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM... AJ AVIATION.... RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
257 PM CST MON JAN 2 2012 .SHORT TERM...TONIGHT THROUGH THURSDAY 257 PM CST MON JAN 2 2012 MAIN FORECAST CONCERNS ARE CLOUD COVER AND TEMPERATURES...ALONG WITH WHETHER PRECIPITATION CAN OCCUR TUESDAY NIGHT. CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED A SHORTWAVE TROUGH OVER THE PACIFIC NORTHWEST...RIDGING FROM THE SOUTHWEST U.S. NORTHWARD INTO SASKATCHEWAN...AND DEEP TROUGHING FROM SOUTHEAST CANADA SOUTHWARD INTO THE SOUTHEAST U.S.. COLD AIR ASSOCIATED WITH THIS DEEP TROUGH IS FIRMLY ENTRENCHED OVER THE FORECAST AREA...WITH 850MB TEMPS PER 12Z RAOBS AROUND -18C. GRB SOUNDING REFLECTS THE COLD ADVECTION SEEN AS WELL...NOTED BY 24 HOUR TEMPERATURE DROP OF 10-15C FROM THE SURFACE TO 400MB. TROPOPAUSE HAS ALSO BEEN LOWERED TO 425MB. CLOUD COVER...RELATED TO MOISTURE STUCK BELOW THE COLD FRONTAL INVERSION NEAR 800MB PER 12Z GRB/MPX SOUNDINGS...HAS BEEN SLOWLY DISSIPATING DUE TO A COMBINATION OF DAYTIME MIXING AND DRY AIR ADVECTING SOUTH OUT OF NORTHERN ONTARIO. TO THE WEST...A RIDGE OF HIGH PRESSURE WAS LOCATED OVER THE EASTERN DAKOTAS. FURTHER WEST...WARM ADVECTION IS TAKING PLACE ALONG THE LEE OF THE ROCKIES...NOTED BY 12Z SOUNDINGS FROM GGW AND UNR WITH 850MB TEMPS AROUND 0C. CIRRUS HAS BEEN PRESENT IN THESE AREAS TOO...COMING FROM PACIFIC MOISTURE TOPPING THE UPPER RIDGING THERE. TONIGHT AND TUESDAY...UPPER RIDGE SEEN OVER MONTANA INTO SASKATCHEWAN IS PROGGED TO PUSH EAST DURING THIS PERIOD...IN RESPONSE TO THE SHORTWAVE TROUGH OVER THE PACIFIC NORTHWEST MOVING INTO WESTERN MINNESOTA BY 00Z WEDNESDAY. THE UPPER RIDGE AXIS SHOULD CROSS THE FORECAST AREA MID-DAY TUESDAY. WITH THE UPPER RIDGING BUILDING IN PROVIDING PLENTY OF SUBSIDENCE...NO PRECIPITATION IS ANTICIPATED. EVEN AFTER THE UPPER RIDGE PASSES LATE TUESDAY AND 500MB HEIGHTS BEGIN TO FALL...THE PRESENCE OF SO MUCH DRY AIR BROUGHT IN BY THE CURRENT UPPER TROUGH WILL KEEP THINGS DRY AND ANY WARM ADVECTION CLOUDS TO MID OR HIGH LEVEL. CONCERN TONIGHT IS HOW LOW TEMPERATURES MAY END UP WITH CLEAR SKIES LIKELY AND THE SURFACE RIDGE MOVING IN OVERNIGHT. WOULD NOT BE SURPRISED IF TYPICAL COLD SITES NORTH OF I-94...WHERE MORE THAN A TRACE OF SNOW EXISTS ON THE GROUND...DROP TO 5 TO 10 BELOW ZERO. MOST OF THE REST OF THE AREA SHOULD SEE LOWS IN THE SINGLE DIGITS ABOVE ZERO...WITH OTHER TYPICAL COLD SPOTS IN WISCONSIN DROPPING TO 0 TO 5 BELOW. INCREASING SOUTH WINDS WILL BRING IN WARMER AIR FOR TUESDAY...CAUSING 850MB TEMPS TO CLIMB TO -2 TO -6C BY 18Z. SOME OF THIS WARM AIR MAY BE CAPPED OFF...HELPED TOO BY THE INCREASE IN MID AND HIGH CLOUDS LATER IN THE DAY PREVENTING MIXING. THEREFORE...HIGHS ARE ONLY FORECAST IN THE 20S. A FEW SITES IN NORTHEAST IOWA COULD TOP 30...THOUGH...CLOSER TO THE WARMEST AIR MOVING IN AND BEING SNOW-FREE. TUESDAY NIGHT THROUGH THURSDAY...SHORTWAVE TROUGH OVER WESTERN MINNESOTA IS WELL AGREED UPON TO MOVE SOUTHEAST ACROSS THE FORECAST AREA TUESDAY NIGHT...WITH 500MB HEIGHTS SLOWLY BUILDING IN ITS WAKE THROUGH THURSDAY. THE RISING HEIGHTS ARE IN RESPONSE TO A SHORTWAVE TROUGH MOVING INTO BRITISH COLUMBIA AND THE PACIFIC NORTHWEST... PUSHING RIDGING THAT DEVELOPED AHEAD OF IT EASTWARD. REGARDING TUESDAY NIGHTS SHORTWAVE TROUGH...NOT IMPRESSED FOR PRECIPITATION. ALTHOUGH DPVA FORCING IS PRETTY DECENT GIVEN THE TRACK...ISENTROPIC LIFT IS VERY WEAK AT BEST AND MOSTLY CONFINED NORTH AND EAST OF OUR FORECAST AREA. IN ADDITION...MOISTURE IS SERIOUSLY LACKING BETWEEN 850-650MB WHICH SHOULD BE ABLE TO ABSORB MOST OF THE SNOW BEING PRODUCED ALOFT. WITH THE 02.12Z NAM/GFS/ECMWF ALL DRY...HAVE PULLED PRECIPITATION CHANCES FOR TUESDAY EVENING...BUT DID LEAVE A MENTION OF FLURRIES IN CASE ANYTHING CAN REACH THE GROUND. AFTER THIS...ONLY ISSUES BECOME CLOUDS/TEMPERATURES WITH NO SYSTEMS EXPECTED TO COME THROUGH TO PRODUCE PRECIPITATION. LOOKS LIKE THERE MAYBE SOME LOW STRATUS IN THE WAKE OF THE TROUGH TUESDAY NIGHT...MAINLY OVER WISCONSIN...WHICH SHOULD CLEAR OUT BY 12Z WEDNESDAY. OTHER BATCHES OF MID/HIGH CLOUD ARE POSSIBLE LATE WEDNESDAY INTO THURSDAY MORNING...MOSTLY ALONG AND EAST OF THE MISSISSIPPI RIVER...INDUCED BY THE WARM ADVECTION PATTERN SET UP BY THE RISING 500MB HEIGHTS. THEREFORE...WHEN IT COMES TO TEMPERATURES...BEST MIXING IS LIKELY TO OCCUR WEST OF THE MISSISSIPPI RIVER. BIGGEST PROBLEM WHEN IT COMES TO TEMPERATURES IS SEEING THE WARM ADVECTION AND HOW MUCH OF IT CAN MIX DOWN. 850MB TEMPS CLIMB TO -2 TO +2C BY 00Z THURSDAY AND 7-11C BY 00Z FRIDAY. WINDS ARE NOT FORECAST TO BE THAT STRONG...5 TO MAYBE 15 KT AT BEST WHICH HURTS MIXING...THOUGH THEY ARE OUT OF THE WEST TO SOUTHWEST WHICH IS A GOOD DIRECTION. CERTAINLY SNOW FREE AREAS COULD GET QUITE WARM FOR THIS TIME OF YEAR. FOR NOW HAVE FOLLOWED A BLEND OF GUIDANCE FOR TEMPERATURES THROUGH THE TUESDAY NIGHT THROUGH THURSDAY TIME PERIOD...BUT RAISED THEM UP A FEW DEGREES FOR HIGHS OVER SNOW-FREE AREAS WEST OF THE MISSISSIPPI RIVER. NOTE... THURSDAYS RECORD HIGH IS 47 AT LA CROSSE AND 45 AT ROCHESTER. THERE IS POTENTIAL TO GET CLOSE TO THIS...ESPECIALLY IF WE ARE SUNNY ALL DAY. .LONG TERM...THURSDAY NIGHT THROUGH MONDAY 257 PM CST MON JAN 2 2012 02.12Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES ARE IN PRETTY GOOD AGREEMENT AGAIN TODAY ON THE UPPER LEVEL AND SURFACE PATTERNS HEADING INTO THE WEEKEND...AND REPRESENT SOLUTIONS SIMILAR TO THOSE SEEN YESTERDAY. GENERAL THEME IS FOR THE WESTERN RIDGING SEEN RECENTLY TO BRIEFLY BREAK DOWN AS A SHORTWAVE COMING OFF THE PACIFIC DIGS DOWN TOWARDS THE FOUR CORNERS REGION ON SATURDAY. MEANWHILE... DOWNSTREAM...THE SHORTWAVE TROUGH THAT WAS IN BRITISH COLUMBIA ON THURSDAY IS FORECAST TO CROSS THE AREA FRIDAY NIGHT...PLACING THE AREA IN TROUGHING FOR THE WEEKEND. NEW RIDGING IS THEN FORECAST TO BUILD OVER THE WESTERN U.S. INTO THE NORTHERN PLAINS FOR SUNDAY NIGHT INTO MONDAY...WHILE SHORTWAVES STREAM SOUTHEAST TOWARDS THE UPPER GREAT LAKES ON THE EDGE OF THIS RIDGING. OVERALL UPPER PATTERN IS UNFAVORABLE FOR MUCH IF ANY PRECIPITATION AS MOISTURE IS VERY LIMITED. ANY MOISTURE IS TRAPPED BY THAT THE SHORTWAVE DROPPING INTO THE FOUR CORNERS REGION...WHICH LOOKS TO CROSS THE GULF COAST SUNDAY INTO MONDAY IN ADDITION...THERE APPEARS TO BE A LACK OF SYSTEMS WITH MUCH FORCING. THEREFORE...A DRY FORECAST CONTINUES THROUGH MONDAY. TEMPERATURES REMAIN THE BIGGEST PROBLEM...ESPECIALLY GIVEN THE UN-CLIMATOLOGICAL LACK OF SNOW ON THE GROUND OVER A LOT OF THE UPPER MIDWEST. A COLD FRONT ASSOCIATED WITH THE SHORTWAVE TROUGH CROSSING THE AREA FRIDAY NIGHT IS PROGGED TO MOVE THROUGH THE AREA FRIDAY MORNING. ALTHOUGH 850MB TEMPS FALL THROUGH THE DAY...FROM 6-10C AT 12Z FRIDAY TO -2 TO +2C BY 00Z SATURDAY...THIS COOLING COMBINED WITH MORE WIND COULD RESULT IN BETTER MIXING THAN THURSDAY. PLUS...WE WILL START OFF WARMER ON FRIDAY. THEREFORE...FRIDAY SHOULD END UP JUST AS WARM AS THURSDAY IF NOT WARMER. COOL DOWN THEN CONTINUES INTO THE WEEKEND AS TROUGHING MOVES OVERHEAD...NOTED BY 850MB TEMPS FALLING TO -5 TO -10C BY 00Z SUNDAY AND -7 TO -10C BY 00Z MONDAY. THE COOL DOWN IS BRIEF...AS THE NEXT WARM UP ENSUES FOR MONDAY WITH THE HEIGHT RISES ALOFT. FOR SATURDAY THROUGH MONDAY...FOLLOWED A BLEND OF GUIDANCE FOR HIGHS AND LOWS. && .AVIATION...THROUGH 18Z TUESDAY 1127 AM CST MON JAN 2 2012 HIGH PRESSURE WILL BUILD INTO THE AREA THIS AFTERNOON INTO THIS EVENING WITH SKIES GRADUALLY CLEARING AT THE TAF SITES. PLAN ON VFR CONDITIONS THROUGH THE FORECAST PERIOD. LOOK FOR NORTHWEST WINDS OF 15 TO 30 KTS LATE THIS AFTERNOON...BECOMING LIGHT AND VARIABLE OVERNIGHT. THE HIGH WILL SLIDE EAST OF THE AREA TUESDAY MORNING AS A TROUGH APPROACHES FROM THE DAKOTAS. WINDS WILL SWITCH TO THE SOUTH BY LATE TUESDAY MORNING. PLAN ON SOUTH WINDS AT 12 TO 20 KTS...WITH GUSTS TO AROUND 27 KTS BY TUESDAY AFTERNOON. HIGH CLOUDS WILL BE ON THE INCREASE TUESDAY MORNING AS THE TROUGH APPROACHES THE REGION...WITH CLOUD BASES IN THE 15 KFT TO 20 KFT RANGE. && .ARX WATCHES/WARNINGS/ADVISORIES... 257 PM CST MON JAN 2 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION.....WETENKAMP
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
221 PM CST MON JAN 2 2012 .SHORT TERM...TONIGHT THROUGH TUESDAY. LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW CYCLONIC FLOW CONTINUING UNABATED OVER THE GREAT LAKES THIS AFTERNOON...WHILE HIGH PRESSURE IS GRADUALLY SHIFTING EAST OVER THE GREAT PLAINS. PLENTY OF LOW LEVEL MOISTURE...STEEP LOW LEVEL LAPSE RATES...AND MOISTURE FLUXES OFF LAKE SUPERIOR ARE CONTRIBUTING TO SCATTERED FLURRIES AND LIGHT SNOW SHOWERS OUTSIDE OF THE LAKE EFFECT SNOW BELT. SPEAKING OF WHICH...1-3SM VISIBILITIES (WITH POCKETS OF LOWER VSBYS) IN SNOW SHOWERS HAVE BEEN PREVAILING WITHIN THE SNOW BELT FOR MUCH OF THE DAY. DRY AIR AS NOTED ON SATELLITE IMAGERY WITH DEWPOINTS SUB-ZERO HAVE BEEN ERODING THE STREAMERS OVER WESTERN LAKE SUPERIOR AND ARE STARTING TO APPROACH THE U.P. SHORELINE. WINDS HAVE BEEN THE BREEZIEST OVER DOOR COUNTY WHERE HAVE SEEN A FEW GUSTS AROUND 39 KTS AT SISTER BAY AND 35 KTS BY ALGOMA. WINTER WEATHER AND WIND HEADLINES ARE THE MAIN FORECAST CONCERN IN THE SHORT TERM. TONIGHT...SURFACE HIGH PRESSURE OVER THE GREAT PLAINS WILL SHIFT EAST TO THE WESTERN GREAT LAKES BY MORNING. AS THE RIDGE AXIS APPROACHES FROM THE WEST...STRONG MID-LEVEL SUBSIDENCE AND LOW LEVEL DRY AIR BROUGHT IN BY NORTH WINDS WILL SHUT DOWN THE LAKE EFFECT PROCESSES OVER WESTERN LAKE SUPERIOR...WHICH WILL CUT OFF THE MOISTURE TRANSPORT FARTHER SOUTH AND EAST. AS A RESULT...WILL SEE CLEARING SKIES THIS EVENING EVEN OVER THE SNOW BELT WHERE LAKE EFFECT STREAMERS WILL BECOME INCREASINGLY CONFINED TO THE U.P. BORDER. WILL LEAVE A SCATTERED MENTION OF SNOW SHOWERS THROUGH MID-EVENING. WILL WAIT UNTIL THE LAST MINUTE TO DECIDE PULL THE WINTER STORM WARNING...AS IT DEPENDS ON VISIBILITIES AND THE DEGREE OF EROSION OF THE LAKE EFFECT BANDS FROM THE DRY AIR. WIND HEADLINES ARE ALSO PROBLEMATIC AS ONLY THE TIP OF THE DOOR HAS BEEN APPROACHING WIND ADVISORY CRITERIA. WINDS SHOULD ONLY GRADUALLY SUBSIDE THIS EVENING...SO ALSO THINK MAY BE ABLE TO PULL THE ADVISORY HEADLINE AT PRESS ISSUANCE. ANOTHER LAST MINUTE DECISION ON THAT ONE. WINDS WILL BE DECOUPLING OVER CENTRAL AND NORTHERN WISCONSIN AFTER MIDNIGHT. WITH THE FRESH SNOW PACK...TEMPS SHOULD PLUMMET LATE TO SOME OF THE COLDEST READINGS OF THE SEASON. BUT BECAUSE WINDS WILL BE DECOUPLING...WIND CHILL READINGS WILL ONLY FALL TO 20 BELOW...WHICH FALLS JUST SHORT OF HEADLINES. TUESDAY...SURFACE HIGH PRESSURE WILL MOVE EAST OF THE AREA BY MIDDAY IN RESPONSE TO SHORTWAVE ENERGY TRACKING OVER THE NORTHERN PLAINS AND NORTHERN MISSISSIPPI VALLEY. WILL SEE MID AND HIGH CLOUDS MOVE OVERHEAD DOWNSTREAM OF THE SHORTWAVE...BUT LOW LEVELS ARE WAY TO DRY FOR PRECIP. AFTER A COLD START TO THE DAY...HIGH TEMPS WILL REBOUND TO THE MID TEENS TO LOW 20S. .LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY. NEXT SYSTEM TO AFFECT THE FORECAST AREA TOWARD TUESDAY NIGHT MAKING LANDFALL ON THE NORTHWEST US COAST TODAY. TREND OF THE LAST FEW MODEL RUNS WITH THIS SYSTEM HAVE BEEN DRY DUE TO LIMITED MOISTURE WHILE WORKING OVER THE ROCKIES...AND MOVING AT GOOD CLIP IN THE FAST NORTHWEST FLOW. THIS FAIRLY DEEP SHARP WAVE TROUGH WITH SURFACE TROUGH REFLECTION HAS A NICE PERIOD OF WAA TUESDAY NIGHT...BUT AVAILABLE LIFT AND MOISTURE WILL MAINLY SERVE TO SATURATE THE AIR MASS...AND THE BEST SNOW GROWTH REGION PASSES QUICKLY OVER. DUE TO CONSISTENT MODEL TO MODEL GUIDANCE OF NO MEASUREABLE QPF...WILL LOWER POPS BUT KEEP A NON MEASURABLE PCPN MENTION GOING. FOR THE REMAINDER OF THE WORK WEEK...THE WESTERN STATES UPPER RIDGE FLATTENS WHILE A SYSTEM PASSES OVER SOUTHERN CANADA. A PERIOD OF WAA WILL RAISE TEMPS ABOVE NORMAL LEVELS THIS WEEK UNTIL A COLD FRONT DROPS OVER LATE IN THE WEEK FOR A RETURN TO MORE NORMAL TEMPERATURES. NORTHWEST FLOW PROVIDES A MINOR LES SNOW CHANCE FOR THE FAR NORTH CENTRAL WISCONSIN FRIDAY NIGHT INTO SATURDAY. ANOTHER NORTHERN STREAM SHORT WAVE TROUGH WITH FRONTAL SYSTEM BRUSHES THE NORTHERN GREAT LAKES REGION TOWARD MONDAY...OTHERWISE THE MEDIUM RANGE MODELS INDICATE NO SIGNIFICANT SYSTEMS TO AFFECT THE AREA THROUGH EARLY NEXT WEEK. && .AVIATION...ONGOING LAKE EFFECT SNOW SHOWERS WILL BE DIMINISHING THIS AFTERNOON...WHICH WILL RESULT IN IMPROVING CONDITIONS AT RHI. STILL WILL HAVE A COUPLE HOURS OF POSSIBLE MVFR CIGS/VSBYS IN SNOW SHOWERS THOUGH. OTHERWISE...THE REST OF THE TAF SITES WILL DEAL WITH SCT/BKN LOW END VFR CIGS WITH A FEW FLURRIES FOR THE REST OF THE AFTERNOON. DRY AIR FROM CANADA WILL WORK ACROSS THE REGION LATE THIS AFTERNOON THROUGH THE EVENING...THAT WILL LEAD TO CLEARING CONDITIONS AND DIMINISHING WIND SPEEDS. WILL HAVE INCREASING MID AND HIGH CLOUDS TOMORROW MORNING...BUT VFR CONDITIONS WILL PREVAIL FROM EARLY THIS EVENING ONWARD. MPC && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MPC/TDH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
315 AM CST MON JAN 2 2012 .SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT 315 AM CST MON JAN 2 2012 MAIN FORECAST CONCERNS THIS PACKAGE...TEMPERATURES THRU THE PERIOD...SMALL -SN CHANCE NORTH TUE EVENING. DATA ANALYSIS AT 06Z HAD A BROAD...STRONG AREA OF LOW PRESSURE CENTERED OVER WESTERN QUEBEC. TIGHT PRESSURE GRADIENT AROUND THIS LOW EXTENDED WESTWARD ACROSS MN/IA/WI INTO THE EASTERN DAKOTAS. WINDS WERE SLOWLY DECREASING...BUT REMAINED NORTHWEST 15-25KTS G25-30KTS ACROSS THE UPPER MIDWEST. BROAD STRATUS CLOUD SHIELD IN THE WAKE OF THE LOW EXTENDED WEST TO NEAR THE MN/ND BORDER TO NEAR KDSM...WITH THE CLEARING EDGE MAKING ONLY SLOW PROGRESS EASTWARD EARLY THIS MORNING. BROAD LOW LEVEL COLD ADVECTION ON THE NORTHWEST FLOW SLOWLY SENDING TEMPS TOWARD MORE NORMAL VALUES FOR EARLY JAN... BUT STILL ABOUT 10F ABOVE NORMAL. 02.00Z MODELS INITIALIZED VERY WELL AND OFFER QUITE SIMILAR SOLUTIONS FOR TODAY THRU WED NIGHT. BIGGEST DETAIL DIFFERENCES LOOK TO BE WITH HANDLING OF LOWER LEVEL MOISTURE/STRATUS CLOUDS/CLEARING OVER THE REGION TODAY. DPROG/DT OF 500MB HGTS AT 02.00Z SHOWED MODEL RUNS OF 31.00Z AND 01.00Z VERIFIED WELL ACROSS NOAM/EASTERN PAC WITH A TREND TOWARD A COMPROMISE/BLEND OF THE EARLIER RUNS ON THE EASTERN CONUS AND EASTERN PAC TROUGHS. THRU TODAY/TONIGHT TREND IS STRONGER/ TIGHTER CONSENSUS ON THE EASTERN CONUS TROUGH AND SLOWER WITH SHORTWAVE HEADING INTO THE NORTHERN PLAINS. CONSENSUS REMAINS GOOD TUE/TUE NIGHT AS THE NORTHERN PLAINS TROUGH DROPS ACROSS THE WESTERN GREAT LAKES...TRENDING TOWARD A COMPROMISE OF THE EARLIER RUNS ON THE STRENGTH OF THIS FEATURE. CONSENSUS IMPROVING FOR WED WED NIGHT AS HGTS RISE/RIDGING ALOFT BUILDS INTO THE NORTHERN PLAINS/UPPER MIDWEST...FAVORING FASTER OF EARLIER RUNS. SOMEWHAT BETTER RUN-TO-RUN CONSISTENCY TO ECMWF THRU THE PERIOD. CHECK OF OBS VS. MODEL DATA AT 06Z SHOWED ALL MODELS QUITE GOOD WITH THE QUEBEC LOW AND PRESSURE GRADIENT ACROSS THE REGION. PER FOG-PRODUCT IMAGERY AND 925-850MB MODEL RH FIELDS...MODELS HAVING SOME DIFFICULTY WITH THE STRATUS SHIELD OVER MN/IA/WI EARLY THIS MORNING. MODEL CONSENSUS TOO DRY WITH THE LOW LEVEL RH. EXCEPTION IS GFS LOOKING TOO MOIST AT 925MB VS. THE SATELLITE IMAGERY. PER WV IMAGERY...MODELS ALL APPEAR REASONABLE WITH THE SHORTWAVE DETAILS ACROSS NOAM/EASTERN PAC. NO CLEAR MODEL FAVORITE THIS CYCLE AND FAVORED A MODEL/ENSEMBLE CONSENSUS. IN SPITE OF SOME CLOUD ISSUES TODAY...SHORT-TERM FCST CONFIDENCE GOOD THIS CYCLE. FOR THE SHORT TERM...AFTER THE VIGOROUS HOLIDAY WEEKEND SYSTEM... SHORT-TERM FOR TODAY THRU WED LOOKING RATHER QUIET. QUEBEC LOW CONTINUES TO MOVE EAST WITH RIDGE OF HIGH PRESSURE FROM THE WESTERN DAKOTAS DRIFTING EAST THRU THE DAY. PRESSURE GRADIENT CONTINUES TO SLOWLY RELAX THRU THE DAY. WITH CONTINUED LOW LEVEL COLD ADVECTION/ SUBSIDENCE...GRADIENT WILL CONTINUE TO SUPPORT NORTHWEST WINDS 15- 25KT G30KTS MUCH OF THE DAY. BIGGER PROBLEM TODAY IS THE CLOUDS/ CLEARING TREND. WITH CLOUDS MUCH MORE WIDESPREAD ACROSS MN/WI/IA THAN BULK OF MODELS...TRENDED TOWARD MORE CLOUD COVER OVER THE AREA AT LEAST THRU THE MORNING. WITH AREA RADARS SHOWING WEAK RETURNS AND SFC OBS OCCASIONALLY REPORTING -SN...ADDED SCT FLURRY MENTION TO NORTHEAST HALF OF THE FCST FOR THIS MORNING. MODEL CONSENSUS INDICATES THE MOISTURE TO BECOME VERY SHALLOW THIS AFTERNOON... EVENTUALLY SUCCUMBING TO THE SUBSIDENCE/COLD ADVECTION. THIS APPEARS TO BE HAPPENING EARLY THIS MORNING WITH THINNING/SCATTERING OF THE CLOUDS OVER FAR NORTHWEST MN...WHICH MODELS SPREAD INTO THE AREA THIS AFTERNOON. COLD/NEAR NORMAL NIGHT ON TAP FOR THE AREA TONIGHT WITH CLEAR SKIES/LIGHT WINDS AS THE SFC RIDGE AXIS DRIFTS ACROSS THE REGION. WITH LACK OF SNOW COVER FOR MUCH OF THE AREA...EVEN WITH IDEAL RADIATIONAL COOLING CONDITIONS...TEMPS ONLY LOOKING TO DIP TO NEAR THE NORMAL LOWS. STRONG LOW LEVEL WARM ADVECTION ALREADY RETURNS FOR TUE AS THE NEXT TROUGH MOVES ACROSS THE DAKOTAS INTO MN AND THE SFC RIDGE AXIS QUICKLY MOVES EAST OF THE REGION. THIS TROUGH AND MID LEVEL SHORTWAVE MOVE ACROSS THE AREA TUE EVENING. SFC-700MB MOISTURE RATHER LIMITED WITH THIS TROUGH. WHAT BETTER COLUMN SATURATION THERE IS AND STRONGER OF FORCING/LIFT PASS ACROSS THE NORTH END OF THE FCST AREA TUE EVENING...BUT 925-700MB LOOKS TO REMAIN TOO DRY FOR PRECIP. LEFT A SMALL -SN CHANCE OVER THE NORTHEAST END OF THE FCST AREA TUE EVENING TO BLEND WITH NEIGHBORING GRIDS. QUICK AND WEAK SHOT OF LOW LEVEL COLD ADVECTION SPREADS ACROSS THE AREA LATER TUE NIGHT/WED MORNING. LOW LEVEL WARM ADVECTION RETURNS/INCREASES FOR LATER WED THRU WED NIGHT WITH THE STORM TRACK SHIFTED INTO CENTRAL CAN. BULK OF THIS GOES INTO WARMING...WITH GOOD MODEL CONSENSUS FOR 925MB TEMPS TO BE IN THE 0C TO +6C RANGE EAST TO WEST ACROSS THE FCST AREA BY 12Z THU. CONSIDERED A NON-DIURNAL TEMP TREND FOR WED NIGHT BUT PRESSURE GRADIENT ON THE WEAK SIDE AND SFC WINDS THRU WED NIGHT LOOKING TO MOSTLY BE 5KTS OR LESS. WITH CLOUDS MUCH OF THE DAY TODAY AND CONTINUED AT LEAST WEAK LOW LEVEL COLD ADVECTION...TEMPS TO BE NEARLY STEADY TODAY. BASED ON 09Z READINGS UNDER THE CLOUDS/LIMITED SNOW COVER...FAVORED WARMER OF GUIDANCE HIGHS TODAY. FAVORED A BLEND OF GUIDANCE LOWS/HIGHS FOR TONIGHT THRU TUE NIGHT. WITH SOME SUN...MIXING AND MOSTLY SNOW-FREE GROUND...TRENDED TOWARD WARMER OF GUIDANCE HIGHS FOR WED. FAVORED A BLEND OF THE GUIDANCE LOWS FOR WED NIGHT FOR NOW. .LONG TERM...THURSDAY THROUGH SUNDAY 315 AM CST MON JAN 2 2012 DAY 4-7 FCST CONFIDENCE AVERAGE TO GOOD. 02.00Z MEDIUM RANGE MODELS IN GOOD AGREEMENT FOR THE RIDGING ALOFT TO BUILD ACROSS THE REGION THU THEN TROUGHING TO MOVE INTO THE NORTHERN PLAINS FRI. STORM TRACK REMAINS IN CENTRAL CAN THU WITH MDT/STRONG LOW LEVEL WARM ADVECTION CONTINUING OVER THE AREA THU INTO THU NIGHT. 925MB TEMPS BY 00Z FRI IN THE +2C TO +10C RANGE. SFC PRESSURE GRADIENT REMAINS MODERATE... WITH LIGHTER WINDS FOR MIXING. MODEL SOUNDINGS SHOWING A RATHER IMPRESSIVE LOW LEVEL INVERSION THU...ALONG WITH HIGHER 500-300MB RH AND POTENTIAL FOR CIRRUS CLOUDS. WEAK/MDT LOWER LEVEL COLD ADVECTION SPREADS IN FOR FRI BEHIND A SFC TROUGH/FRONTAL PASSAGE BUT 925MB TEMPS REMAIN ABOVE 0C/WELL ABOVE NORMAL THRU 00Z SAT. TEMPS THU/FRI CONTINUE TO TREND TOWARD MUCH ABOVE NORMAL FOR EARLY JAN BUT JUST HOW MUCH REMAINS IN QUESTION. FOR NOW FAVORED THE MODEL CONSENSUS ON THU/FRI HIGHS GIVEN SIGNIFICANT IMPACT ANY CLOUDS OR STRENGTH OF MIXING WINDS COULD HAVE ON THEM. HGTS FALL ACROSS THE NORTH-CENTRAL CONUS FOR SAT/SUN WITH BROAD TROUGHING DEVELOPING OVER CENTRAL/ EASTERN NOAM. SECONDARY TROUGH/COLD FRONT DROPS THRU THE REGION SAT WITH THE AREA RECEIVING A GLANCING BLOW OF COLDER AIR. PATTERN REMAINS PROGRESSIVE WITH LOWER LEVEL WARM ADVECTION ALREADY RETURNING FOR SUN AS THE STORM TRACK REMAINS NORTH IN CANADA. SAT/ SUN LOOKING TO REMAIN DRY WITH TEMPS NEAR OR ABOVE NORMAL. A MODEL CONSENSUS/BLEND FOR THE DAY 6/7 FCST GRIDS LOOKS GOOD AT THIS TIME. && .AVIATION...THROUGH 06Z TUESDAY 1137 PM CST SUN JAN 1 2012 MAIN FORECAST CONCERNS REMAIN ON WINDS THROUGH MONDAY AND TIMING OF CLEARING TREND. PRESSURE GRADIENT WILL REMAIN RATHER TIGHT THROUGH MONDAY AND STILL EXPECT THE NORTHWEST WINDS TO GUST TO NEAR 30 TO 35 KNOTS THROUGH AT LEAST MID AFTERNOON MONDAY BEFORE DIMINISHING RAPIDLY DURING THE EARLY EVENING HOURS AS RIDGE AXIS BUILDS INTO THE AREA. CEILINGS HAVE BEEN VERY CONSISTENT THIS EVENING IN THE 025K-035K FOOT RANGE. LOOKING UPSTREAM OF THE TAF SITES FEEL THIS TREND WILL CONTINUE THROUGH THE OVERNIGHT HOURS AND THEN BEGIN TO RISE INTO VFR AFTER 14Z MONDAY. LATEST 02.03Z RUC BUFKIT SOUNDINGS SHOW CLOUDS TO BEGIN TO SCATTERED OUT MONDAY MORNING FROM THE WEST. THIS A LITTLE SLOWER THAN PREVIOUSLY THOUGHT AND DID BACK CLEARING UP AT KRST UNTIL 16Z...WITH KLSE AROUND 20Z. && .ARX WATCHES/WARNINGS/ADVISORIES... 315 AM CST MON JAN 2 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...RRS LONG TERM....RRS AVIATION.....RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1137 PM CST SUN JAN 1 2012 .SHORT TERM... 1137 PM CST SUN JAN 1 2012 ALTHOUGH PRESSURE GRADIENT WILL REMAIN TIGHT OVERNIGHT...SURFACE REPORTS INDICATE WINDS HAVE DROPPED JUST BELOW ADVISORY CRITERIA. THUS WILL BE ALLOWING THE WIND ADVISORY TO EXPIRE AS SCHEDULED AT MIDNIGHT. STILL COULD SEE SOME ISOLATED GUSTS TO AROUND 40 MPH. WILL HAVE UPDATED PRODUCTS OUR BY THE TOP OF THE HOUR. .LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY 304 PM CST SUN JAN 1 2012 01.12Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES ARE GENERALLY IN GOOD AGREEMENT THROUGH THE ENTIRE LONG TERM PERIOD. UPPER RIDGING THAT HAS BEEN PRESENT OVER THE WESTERN U.S. IS STILL SHOWN TO FLATTEN OUT AND PUSH EAST...IN RESPONSE TO A FAIRLY POTENT TROUGH COMING INTO SOUTHWEST CANADA AROUND 00Z FRIDAY. THIS UPPER RIDGING WILL BRING WITH IT 850MB TEMPS THAT ARE AROUND 2 STANDARD DEVIATIONS ABOVE NORMAL INTO THE FORECAST AREA FRIDAY MORNING. THE SURFACE WARM FRONT LEADING THE WARMER AIR LOOKS TO MOVE THROUGH THE AREA THURSDAY NIGHT. MAY SEE SOME MID AND HIGH CLOUDS AHEAD OF THE WARM FRONT FOR WEDNESDAY NIGHT AND THURSDAY...BUT NO PRECIPITATION IS ANTICIPATED DUE TO PLENTY OF LOW LEVEL DRY AIR. COLD FRONT MOVES THROUGH DURING THE DAY FRIDAY WITH LITTLE FANFARE. THE FRONT WILL BRING IN SOME COOLER AIR...KNOCKING 850MB TEMPS DOWN FROM THE 8-10C READINGS AT 12Z FRIDAY TO PERHAPS AS COOL AS 2-6C BY 00Z SATURDAY. HOWEVER...THE FRONT MAY ACTUALLY HELP TO PRODUCE BETTER MIXING. WITH MOSTLY SUNNY SKIES ANTICIPATED ON FRIDAY...READINGS IN THE 40S ARE LIKELY WITH 50S CERTAINLY NOT OUT OF THE QUESTION. COLDEST READINGS EXPECTED OVER NORTH CENTRAL WISCONSIN...WHILE WARMEST READINGS WOULD OCCUR OVER NORTHEAST IOWA. FOR NEXT WEEKEND...BROAD TROUGHING DEVELOPS FROM THE SOUTHWESTERN U.S. INTO ONTARIO...WITH SOME INDICATIONS THAT IT MAY SPLIT INTO TWO PIECES. MUCH OF THIS TROUGHING FORMS FROM THAT POTENT TROUGH...WHICH IS DIGGING INTO THE NORTHERN PLAINS AND SOUTH CENTRAL CANADA ON FRIDAY. THIS TROUGHING COMING INTO THE FORECAST AREA WILL ALLOW FOR COLDER AIR TO MOVE INTO THE AREA. 850MB TEMPS ARE PROGGED TO DROP TO -6 TO -10C BY 00Z SUNDAY AND AT LEAST -10 TO -14C BY 00Z MONDAY. NOTE...THE 01.12Z ECMWF NOW SHOWS WARMER CONDITIONS...WITH 850MB TEMPS ONLY DROPPING TO 0 TO -3C BY 00Z SUNDAY AND -4 TO -8C BY 00Z MONDAY. THEREFORE...IT IS POSSIBLE THAT THE WEEKEND MIGHT BE A LITTLE WARMER THAN FORECAST. DESPITE THE COOLING...NOT A LOT OF MOISTURE LOOKS TO ACCOMPANYING THE TROUGH...SO DRY CONDITIONS ARE FORECAST AT THIS TIME. && .AVIATION...THROUGH 06Z TUESDAY 1137 PM CST SUN JAN 1 2012 MAIN FORECAST CONCERNS REMAIN ON WINDS THROUGH MONDAY AND TIMING OF CLEARING TREND. PRESSURE GRADIENT WILL REMAIN RATHER TIGHT THROUGH MONDAY AND STILL EXPECT THE NORTHWEST WINDS TO GUST TO NEAR 30 TO 35 KNOTS THROUGH AT LEAST MID AFTERNOON MONDAY BEFORE DIMINISHING RAPIDLY DURING THE EARLY EVENING HOURS AS RIDGE AXIS BUILDS INTO THE AREA. CEILINGS HAVE BEEN VERY CONSISTENT THIS EVENING IN THE 025K-035K FOOT RANGE. LOOKING UPSTREAM OF THE TAF SITES FEEL THIS TREND WILL CONTINUE THROUGH THE OVERNIGHT HOURS AND THEN BEGIN TO RISE INTO VFR AFTER 14Z MONDAY. LATEST 02.03Z RUC BUFKIT SOUNDINGS SHOW CLOUDS TO BEGIN TO SCATTERED OUT MONDAY MORNING FROM THE WEST. THIS A LITTLE SLOWER THAN PREVIOUSLY THOUGHT AND DID BACK CLEARING UP AT KRST UNTIL 16Z...WITH KLSE AROUND 20Z. && .ARX WATCHES/WARNINGS/ADVISORIES... 1137 PM CST SUN JAN 1 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...RABERDING LONG TERM...AJ AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1029 PM CST SUN JAN 1 2012 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .UPDATE...AM GOING TO BUFFER THE WS.W FOR VILAS WITH A WW.Y FOR ONEIDA...FOREST...AND FLORENCE COUNTIES. OBS FM N-C WI CONT TO SUGGEST NASTY CONDITIONS DUE TO SHSN AND SOME BLSN/DRSN. WINDS AT 925/850 MB STILL IN THE PROCESS OF VEERING INTO A MORE FAVORABLE TRAJECTORY...AND COLDER AIR ARRIVING OVER THE LAKE. RADAR MOSAIC SUGGESTS AN INCR IN LAKE-EFFECT COMING INLAND FM WRN LAKE SUPERIOR THE PAST COUPLE HRS. MOST IMPORTANTLY...THE AIR UPSTREAM FM THE LAKE IS STILL MOIST...AND SYNOPTIC FORCING STILL GENERATING SOME SHSN NW OF THE LAKE. SO THE ARRIVAL OF THE COLDER AIR WON/T BE OFFSET BY DRYING AS IS OFTEN THE CASE. THIS SURE ISN/T A GIVEN...BUT HEADLINES FOR LAKE-EFFECT IN N-C WI GENERALLY ARE NOT. GIVEN THE OVERALL EVOLUTION OF THE SITN...CONDITIONS WL LIKELY BE BAD ENOUGH TO SUPPORT A HEADLINE RATHER THAN TRYING TO GET BY WITH JUST STATEMENTS. WL MAKE SOME TWEAKS...BUT NO SIG CHGS...TO THE FCST FOR THE REST OF THE AREA. WINDS STILL NOT COMING UP MUCH IN DOOR COUNTY. BUT A CONT VEERING WL BRING THEM TO A MORE FAVORABLE NNWLY TRAJECTORY... AND CAA SHOULD DEEPEN THE MIXED LAYER. SO WL STAY THE COURSE WITH THE DOOR COUNTY WI.Y. UPDATED PRODUCT SUITE WL BE OUT ASAP. NO CHGS TO THE NPW NOW...WL FRESHEN THE WORDING LATER...BUT DON/T ANTICIPATE CONTENT CHGS TO THAT YET. SKOWRONSKI && .PREV DISCUSSION...ISSUED AT 643 PM CST SUN JAN 1 2012... UPDATE...NOT MEETING WIND ADVISORY CRITERIA ANYWHERE IN THE FCST AREA. THE CLOSEST WAS THE MOST RECENT IMT OB...BUT EVEN THAT WAS BLO CRITERIA. SOME INCR IN CAA EXPECTED DURING THE EVENING. BUT 925 MPH WINDS PROGGED TO PEAK WITHIN THE NEXT FEW HRS AND THEN START TO SLOWLY EDGE BACK DOWN. GIVEN HOW FAR WE ARE FROM ADVISORY CRITERIA AT MOST LCNS RIGHT NOW...HARD TO SEE ANYTHING MORE THAN AN ISOLD OB GETTING EVEN CLOSE. IT/S CERTAINLY NOT GOING TO BE A COMFORTABLE EVENING TO BE OUTSIDE AND DON/T WANT TO SPLIT HAIRS OVER EXACT CRITERIA...BUT MY OVERALL FEEL FOR THE SITN IS THAT WE JUST AREN/T CLOSE ENOUGH TO TRY AND RIDE THE ADVISORY UNTIL MIDNIGHT. SO WL DROP IT FOR ALL BUT THE DOOR. CAA ALOFT ARRIVING ALOFT OVER THE UNFROZEN NRN BAY WL DEEPEN THE MIXING OVER THE DOOR...SO SHOULD STILL GET SOME INCR IN WINDS THERE. WL MAINTAIN THE ADVISORY FOR DOOR COUNTY. UPDATED PRODUCT SUITE WL BE OUT ASAP. SKOWRONSKI DISCUSSION ISSUED AT 514 PM CST SUN JAN 1 2012... SHORT TERM...TONIGHT AND MONDAY. LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE MOVING TO THE NORTHEAST OVER LAKE HURON THIS AFTERNOON WHILE HIGH PRESSURE HAS SETTLED OVER THE FRONT RANGE OF THE ROCKIES. STRONG SHORTWAVE OVER SOUTHERN WISCONSIN IS CONTRIBUTING TO WIDESPREAD SNOW SHOWERS AND FLURRIES ACROSS THE REGION...BUT THE SNOW SHOWERS EXIST ALL THE WAY BACK TO NORTHERN MINNESOTA AND SW ONTARIO. LAKE EFFECT SNOWS REMAIN NORTH OF THE U.P. BORDER SO FAR...BUT WITH SOME IMPRESSIVE BANDS ON THE MQT RADAR. MEANWHILE...WIND GUSTS THIS AFTERNOON HAVE REMAINED WELL BELOW ADVISORY CRITERIA SO FAR. HAVE HAD A FEW GUSTS IN THE 34-37 KT RANGE OVER CENTRAL WISCONSIN LATE THIS MORNING...BUT HAVE SINCE DIMINISHED. HEADLINES AND SNOW AMOUNTS REMAIN THE MAIN FORECAST CONCERN IN THE SHORT TERM. TONIGHT...LOW PRESSURE WILL EXIT THE REGION INTO QUEBEC WHILE ARCTIC HIGH PRESSURE MOVES EAST OVER THE GREAT PLAINS. A TIGHT PRESSURE GRADIENT WILL REMAIN IN PLACE BETWEEN THESE TWO FEATURES WITH 0-1KM AGL WIND SPEEDS AROUND 35 KTS. DESPITE THE COLD ADVECTION TODAY...WIND GUSTS HAVE BEHAVED AND HAVE ONLY BRIEFLY APPROACHED ADVISORY CRITERIA OVER CENTRAL WISCONSIN. WILL MONITOR WIND GUSTS UNTIL THE LAST MINUTE BEFORE MAKING HEADLINE DECISIONS ON THE WIND ADVISORY. AFTER COORDINATION...WILL LEAVE WIND HEADLINES IN PLACE AS A TIGHT PRESSURE GRADIENT UPSTREAM AND COLD ADVECTION CONTINUES. STILL PLENTY GOING ON BESIDES THE GUSTY WINDS. SHORTWAVE TROUGH NEAR MSN WILL BE EXITING OVER SOUTHERN LAKE MICHIGAN DURING THE EVENING. ANOTHER SHEARED WAVE OVER LAKE WINNIPEG WILL DIVE SOUTHEAST OVER THE NORTHERN MISSISSIPPI VALLEY TONIGHT AND KEEP WEAK QG FORCING IN PLACE. COMBINED WITH 1-3SM SNOW OBS ALL THE WAY NORTH OF INTERNATIONAL FALLS AND SATURATION OF THE COLUMN ABOVE THE -10C LINE IN PROGGED SOUNDINGS...WILL LEAVE A SCATTERED SNOW SHOWER MENTION ACROSS THE FORECAST AREA FOR THE DURATION OF THE EVENING. THE BIGGEST IMPACT WILL BE THE LAKE EFFECT SNOW OVER NORTH-CENTRAL WISCONSIN. CONDITIONS WILL BE IMPROVING FOR SIGNIFICANT ACCUMULATIONS THROUGH THE NIGHT. MAY NOT BE A WHOLE LOT OF IMPACT THIS EVENING...AS WIND DIRECTIONS OF 320-330 ARE NOT CONDUCIVE FOR ACCUMS EXCEPT ALONG THE U.P. BORDER. BUT TRAJECTORIES WILL VEER SLIGHTLY TO 340 DEGREES BY 12Z MONDAY. WITH DELTA T/S IN THE UPPER TEENS AND 850-700MB MOISTURE OF 80 PCT...SHOULD SEE GOOD DENDRITIC SNOW GROWTH TO GENERATE A HALF INCH TO ONE INCH PER HOUR SNOWFALL RATES BY THIS TIME. WILL LOWER SNOW AMOUNTS IN THE EVENING...BUT KEEP THEM AROUND 2-3 INCHES DURING THE OVERNIGHT PERIOD. THIS WILL YIELD 3-5 INCH AMOUNTS...HIGHEST OVER THE NORTHERN PART OF VILAS COUNTY. MONDAY...THE LAKE EFFECT SHOW WILL CONTINUE OVER N-C WISCONSIN DURING THE MORNING. BUT CONDITIONS WILL TURN INCREASINGLY HOSTILE DURING THE 15-18Z TIMEFRAME AS DRY ARCTIC AIR FLOWS OVER WESTERN LAKE SUPERIOR. AS A RESULT...SNOWFALL RATES SHOULD BE DIMINISHING BY MIDDAY AND THROUGH THE AFTERNOON...AS THE DRY AIR SURGES SOUTHEAST. WILL GO WITH AN ADDITIONAL 2-4 INCHES IN THE FORECAST. CLOUDY TO MOSTLY CLOUDY CONDITIONS WILL EXIST ELSEWHERE. LEFT AN ISOLATED FLURRY MENTION GOING FOR THE MORNING BEFORE THE DRIER AIR ARRIVES. SOME BREAKS IN THE CLOUDS ARE LIKELY MID TO LATE AFTERNOON. HIGHS RANGING FROM THE LOWER TEENS TO LOWER 20S. LONG TERM...MONDAY NIGHT THROUGH SATURDAY. SURFACE RIDGE WILL GRADUALLY DRIFT INTO THE FORECAST AREA MONDAY NIGHT. SUBSTANTIAL DRYING AND STRONG SUBSIDENCE SHOULD PRETTY MUCH PUT AN END TO ANY LAKE EFFECT SNOW FOR VILAS COUNTY BY EARLY MONDAY EVENING. JUST KEPT A FEW LINGERING FLURRIES FOR FAR NORTHERN VILAS BEFORE 06Z THEN DRY THERAFTER. STILL APPEARS MONDAY NIGHT WILL BE THE COLDEST NIGHT WE HAVE SEEN THIS SEASON WITH MIN TEMPS EASILY FALLING INTO THE MIDDLE NEGATIVE TEENS ACROSS NORTHCENTRAL OVERNIGHT GIVEN FRESH SNOW COVER THAT WAS RECEIEIVED EARLY SUNDAY. SHORTWAVE DISTURBANCE THEN QUICKLY DIVES SOUTHEAST INTO THE WESTERN GREAT LAKES BY 00Z WEDNESDAY. AFTER A SUNNY AND COLD START...WARM ADVECTION AHEAD OF THIS SYSTEM WILL LIKELY BRING IN SOME MID TO HIGH-LEVEL CLOUDS DURING THE DAY ON TUESDAY. GIVEN THE COLD START AND INCREASING CLOUDS LATER IN THE DAY...MAX TEMPS WILL LIKELY NOT BE ABLE RISE MUCH PAST THE MIDDLE TEENS. AS PER PREVIOUS FORECAST...STILL APPEARS LOW CHANCE POPS ARE WARRANTED FOR FOR AT LEAST THE NORTHERN HALF OF THE FORECAST AREA. APPEARS SYSTEM MAY BE A BIT FASTER THAN PREVIOUS MODEL RUNS THUS FOCUSED HIGHEST POPS IN THE 00Z TO 06Z TIME FRAME. PRECIP AMOUNTS APPEAR MINIMAL WITH LIGHT SNOW OR SNOW SHOWERS PROVIDING LITTLE IF ANY ACCUMULATION OVERNIGHT. DURING THE LATER HALF OF THE WORK WEEK BROAD RIDGE OVER THE WESTERN CONUS GRADUALLY FLATTENS AND BECOMES MORE ZONAL AS SEVERAL PIECES OF ENERGY MOVE ONSHORE OVER THE WEST COAST OF THE U.S. THIS SHOULD LEAD TO A GENERAL BENIGN PERIOD WITH TEMPERATURES AT OR ABOVE NORMAL STARTING WEDNESDAY...AND MODERATING FURTHER TO NEAR 40 BY WEEKS END. FAIRLY LARGE DESCREPANCY IN THE MEDIUM RANGE MODELS FOR FRIDAY INTO THE WEEKEND ON SYSTEM MOVING ACROSS SOUTHERN CANADA. PREFER MUCH WEAKER AND MORE ZONAL-LOOKING ECMWF/CANADIAN. THUS KEPT FORECAST MAINLY DRY AND LEANED SLIGHTLY WARMER THAN MODEL BLEND ESPECIALLY FOR SATURDAY. && .AVIATION...LITTLE CHG IN CONDITIONS EXPECTED THE NEXT 12 HRS. SCT SW- WL GRADUALLY DIMINISH TO SW-- EXCEPT IN THE SNOWBELT. WENT A LITTLE SLOWER THAN GUID IS INDICATING FOR CLEARING TOMORROW GIVEN FLOW DOWN OFF SUPERIOR. SKOWRONSKI && .GRB WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL NOON CST MONDAY FOR WIZ010>012. WIND ADVISORY UNTIL 6 PM CST MONDAY FOR WIZ022. WINTER STORM WARNING UNTIL 3 PM CST MONDAY FOR WIZ005. && $$
AREA FORECAST DISCUSSION
NWS ALBANY NY
346 AM EST WED JAN 4 2012 .SYNOPSIS... THE HIGH PRESSURE SYSTEM RESPONSIBLE FOR OUR ARCTIC AIR MASS WILL MOVE EAST TODAY...THE AIR MASS WILL BEGIN TO SLOWLY MODERATE THROUGH THE END OF THE WEEK. A FEW WEAK DISTURBANCES WILL PASS THROUGH OVER THE NEXT FEW DAYS...WITH JUST A CHANCE OF MAINLY LIGHT SNOW SHOWERS AND FLURRIES. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SURFACE WARM FRONT WAS APPROACHING FROM THE CENTRAL GREAT LAKES REGION THIS MORNING. UPSTREAM REGIONAL RADAR MOSAIC REVEALS MINIMAL ACTIVITY...HOWEVER...MAIN UPPER SUPPORT PER THE H2O VAPOR LOOP HAS YET TO FULLY INTERACT WITH THIS SURFACE FEATURE. NCEP MODEL SUITE AND HOURLY RUC13 SUPPORT AN OVERALL INCREASE IN LIFT /AGAIN LIKELY DUE TO THE WARM ADVECTIVE PROCESSES/ AND MOISTENING OF THE ATMOSPHERIC COLUMN. QG VERTICAL MOTIONS DO SUGGEST THE POTENTIAL FOR FLURRIES AS THIS WILL BE PLACED IN THE GRIDS/FORECAST. ONCE THE SURFACE WARM FRONTAL BOUNDARY LIFTS NORTHWARD...MARGINAL LAKE INSTABILITY AND FAVORABLE WIND TRAJECTORIES POINT TOWARD LAKE EFFECT/ENHANCED SNOW SHOWERS DOWNWIND OF LAKE ONTARIO INTO PORTIONS OF THE DACKS. LOW LEVEL CONVERGENCE FIELDS INCREASE AS HIRES QPF SUGGEST ACCUMULATIONS WILL BE MINOR. AFTER A VERY CHILLY START TO THE DAY...WE SHOULD REBOUND BACK INTO THE 20S FOR THE MAJORITY OF THE CWFA THIS AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... LAKE RESPONSE WILL CONTINUE TONIGHT...YET INVERSION LEVELS ARE LESS THAN IDEAL FOR TALL CONVECTIVE GROWTH AND TOO MUCH SHEAR SEEN IN THE PROFILES. NEVERTHELESS...AS ANOTHER COLD FRONT APPROACHES FROM ONTARIO PROVINCE...THIS WILL ENHANCE THE LOW LEVEL CONVERGENCE OVER LAKE ONTARIO FOR A BAND/S/ OF SNOW TO CONCENTRATE INTO THE DACKS. THIS BAND/S/ WILL MIGRATE SOUTH OVERNIGHT AS THAT COLD FRONT SLIDES SOUTHWARD TOWARD SUNRISE THURSDAY. AS AMPLE LOW LEVEL STRATUS WILL BE IN PLACE ACROSS THE REGION...TEMPERATURES WILL NOT DROP TOO MUCH TO KEEP DIURNAL RANGES RATHER SMALL. ON THURSDAY...COLD FRONT SLIDES SOUTHEAST OF THE CWFA WITH RIDGING REESTABLISHING ITSELF OVER THE EASTERN GREAT LAKES. THIS WILL LIMIT LAKE EFFECT ACTIVITY AS WE WILL KEEP CHANCE POPS FOR PORTIONS OF THE MOHAWK VALLEY...SCHOHARIE VALLEY AND EASTERN CATSKILLS. TEMPERATURES SHOULD REBOUND FURTHER WITH MAINLY LOW-MID 30S FOR THE VALLEY LOCATIONS AND MID-UPR 20S FOR THE HIGHER TERRAIN. UPSTREAM...PACIFIC SYSTEM COMES ASHORE AND MOVES ACROSS SOUTHERN CANADA LATE THURSDAY INTO FRIDAY. THIS WILL AID IN AN INCREASE OF MID LEVEL WARM ADVECTION AND TIGHTENING OF THE BAROCLINIC ZONE OVER THE GREAT LAKES REGION. ISENTROPIC LIFT INCREASES THURSDAY NIGHT WITH THE CHANCE FOR LIGHT SNOW EVOLVING ALONG AND NORTH OF I90 WHICH CONTINUES INTO FRIDAY. AS THERMAL PROFILES CONTINUE TO WARM...PRECIPITATION IS EXPECTED TO MIX WITH RAIN DURING FRIDAY. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THERE IS ACTUALLY A FAIR AMOUNT OF AGREEMENT DURING AT LEAST THE FIRST OF THE EXTENDED PERIOD AMONGST THE GLOBAL FORECAST MODEL (GFS)/CANADIAN METEOROLOGICAL CENTER MODEL (CMC) AND THE EUROPEAN CENTER MID RANGE WEATHER FORECAST (ECMWF). THAT SAID...DUE TO LACK OF ANY STRONG SHORT WAVES UPSTREAM IN THE PACIFIC...AND THE FACT THAT THE SOUTHERN JETSTREAM AND NORTHERN JETSTREAM REMAIN BIFURCATED AS THEY HAVE BEEN MOST OF THIS YOUNG WINTER SEASON...FORECAST CONFIDENCE IS ONLY AT A MEDIUM LEVEL. THE PERIOD STARTS OUT WITH A CLIPPER TYPE STORM PROJECTED TO MOVE NORTH OF THE REGION...POSSIBLY LINGERING SNOW SHOWERS OVER THE NORTHERN HALF OF OUR FORECAST REGION FRIDAY NIGHT. SATURDAY THIS SYSTEM MOVES OFF THE CANADIAN MARITIMES AND IN ITS WAKE...RELATIVELY MILD AIR BY JANUARY STANDARDS...FEATURING H850 AT OR A LITTLE ABOVE 0C...WILL BE OVER THE REGION. THERE COULD BE A FEW LIGHT SHOWERS OR RAIN OR SNOW WELL WEST OF THE CAPITAL REGION AHEAD OF AN INCOMING COLD FRONT. ANY ISOLATED/SCATTERED SHOWER ACTIVITY LOOKS LIGHT. A TRAILING COLD FRONT LOOKS TO MOVE THROUGH SATURDAY NIGHT WHICH BRING A SLIGHT CHANCES OF ADDITIONAL LIGHT SHOWERS OF RAIN OR SNOW ACROSS THE REGION...EXCEPT LOW CHANCES OF SNOW ACROSS THE ELEVATED TERRAIN TO OUR WEST. BY SUNDAY...IT LOOKS AS THIS BOUNDARY WILL LAY DOWN SOMEWHERE TO OUR SOUTH AND STALL. WEAK CANADIAN HIGH PRESSURE ATTEMPTS TO BUILD IN. EARLIER RUNS OF THE ECMWF INDICATE A SOMEWHAT POTENTIALLY POTENT WAVE COULD RIDE UP ALONG THIS BOUNDARY AND BRING A ROUND OF SNOW OR MIXED PRECIPITATION. HOWEVER...THE 00Z ECMWF HAS FALLEN IN LINE WITH THE CMC AND GFS WHICH HAVE BOTH INDICATED ANY WAVE TO BE WEAKER AND FURTHER SOUTH. THE TIMING OF THIS WAVE IS SLOWER WITH THE GFS COMPARED TO THE OTHER MODELS MOVING OFF TO OUR SOUTH MONDAY INSTEAD OF SUNDAY. NEVERTHELESS...THE EUROPEAN ENSEMBLES INDICATE A VARIETY OF SOLUTIONS...NOT SURPRISING THIS FAR OUT AS THERE IS STILL A POTENTIAL FOR ENERGY FROM BOTH THE NORTHERN AND SOUTHERN JETSTREAMS TO PHASE. THIS SCENARIO WILL BE WATCHED BUT FOR NOW ONLY KEEP SLIGHT TO LOW CHANCES SUNDAY INTO MONDAY AS IF NOTHING ELSE...AN NORTHEAST FLOW MIGHT KEEP CLOUDS AND LIGHT SPOTTY PRECIPITATION AROUND. BY TUESDAY...ALL THE MODELS INDICATE WHATEVER SYSTEM IS TO OUR EAST AND WEAK HIGH PRESSURE BUILDS IN. TEMPERATURES LOOK TO RUN A LITTLE ABOVE NORMAL DURING THE EXTENDED PERIOD. SATURDAY LOOKS TO BE MILDEST DAY WITH HIGHS CLIMBING INTO THE 40S MOST PLACES...WITH 30S CONFINED TO THE HIGHEST TERRAIN INCLUDING ALL OF THE ADIRONDACK PARK. THE REMAINDER OF THE DAYS WILL SEE HIGHS RANGING FROM THE 30S TO NEAR 40 VALLEYS AREAS...MID 20S TO LOWER 30S HIGHER TERRAIN. OVERNIGHT LOWS WILL GENERALLY BE IN THE 20S DURING THE EXTENDED PERIODS...TEENS ADIRONDACKS. PRECIPITATION AMOUNTS LOOK TO BE A LITTLE BELOW NORMAL...BUT THAT COULD EASILY CHANGE IF ENERGY FROM THE JETSTREAMS HAS THE OPPORTUNITY TO PHASE AT ANY GIVEN TIME DURING THE EXTENDED PERIOD. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... VFR CONDITIONS LIKELY TO PREVAIL AT ALL TAF SITES THROUGH TODAY. ARCTIC HIGH PRESSURE WILL CREST OVER THE TAF SITES OVERNIGHT INTO EARLY WEDNESDAY WITH GENERALLY UNLIMITED VISIBILITY AND NO REAL SENSIBLE CLOUDS. THE GUSTY NW WIND WILL RELAX...BECOMING LIGHT AND VARIABLE UNDER 5KTS TOWARD DAYBREAK. THE WIND WILL TURN SOUTHERLY LATER WEDNESDAY MORNING AS THE HIGH DEPARTS TO OUR EAST AVERAGING 5-10KTS...PERHAPS A BIT GUSTY AT KALB BY AFTERNOON. SATELLITE PICTURES DO SHOW LAKE EFFECT CLOUDS STILL TO THE WEST OF OF KALB. ALL INDICATIONS ARE THAT THIS PLUME OF MVFR CLOUDS WILL STAY TO THE WEST OF ALBANY BUT IT IS REMOTELY POSSIBLE THEY COULD BRIEFLY SPREAD TO THE AIRPORT THROUGH DAYBREAK. SINCE THE CHANCE OF THIS HAPPENING IS WELL UNDER 50 PERCENT...DID NOT INCLUDE IN A TEMPO GROUP. AGAIN...WE WOULD BE TALKING AT WORST MVFR CIGS WITH PERHAPS A FEW FLURRIES. LATER ON WEDNESDAY HIGH OR MID LEVEL CLOUDS WILL OVERSPREAD THE REGION. THIS MIGHT PRODUCE A FEW SNOW SHOWERS AFTER DARK. OUTLOOK... WED NT...VFR. CHC MVFR -SHSN. THU...VFR. CHC MVFR -SHSN. THU NT...VFR. NO SIG WX. FRI...VFR. CHC MVFR NORTH OF KPOU WITH -SN. SAT...VFR. NO SIG WX. SUN...VFR. CHC MVFR -RA/-SN. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE REMAINDER OF THIS WEEK. AN ARCTIC AIR MASS RESIDES OVER THE REGION AT THE MOMENT. COLD TEMPERATURES ALONG WITH BRISK WINDS WILL AID IN THE FORMATION OF ICE ON MANY BODIES OF WATER THIS WEEK. ANY PRECIPITATION THAT FALLS THROUGH SATURDAY WILL BE LIGHT AND IN THE FORM OF MAINLY SNOW. 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...WIND CHILL ADVISORY UNTIL 9 AM EST THIS MORNING FOR CTZ001. NY...WIND CHILL ADVISORY UNTIL 9 AM EST THIS MORNING FOR NYZ032-033- 042-058-063-082. MA...WIND CHILL ADVISORY UNTIL 9 AM EST THIS MORNING FOR MAZ001-025. VT...NONE. && $$ SYNOPSIS...BGM NEAR TERM...BGM SHORT TERM...BGM LONG TERM...HWJIV AVIATION...HWJIV HYDROLOGY...BGM FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1225 AM EST WED JAN 4 2012 UPDATED FOR 06Z AVIATION DISCUSSION .UPDATE... GIVEN RECENT IR SATELLITE TRENDS AND FAIRLY DRY LOOK OF 00Z AREA SNDGS...DECIDED TO UPDATE FOR LESS PESSIMISTIC CLOUD CONDITIONS FOR MUCH OF THE CWA FOR THE REST OF TONIGHT. WITH THE EXCEPTION OF THE KEWEENAW PENINSULA (WHERE UPSLOPE FLOW WILL MORE FAVORABLE FOR CLOUDS AND LIGHT MIXED PCPN)...WENT WITH MORE CLEARING OVERNIGHT AND ALSO REMOVED MENTION OF LIGHT SNOW AND PATCHY FZDZ. GENERALLY TRENDED MIN TEMPS DOWNWARD A FEW MORE DEGREES GIVEN LONGER EXPECTED PERIOD OF CLEAR SKIES. LOOK FOR MINS APPROACHING 10F OVER WESTERN INTERIOR COLD SPOT LOCATIONS. && PREV DISCUSSION...ISSUED AT 651 PM EST TUE JAN 3 2012... .SHORT TERM /TONIGHT AND WED/... WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW THE NEXT SHORTWAVE TROF OF INTEREST HEADING SE THRU MANITOBA AND THE DAKOTAS. IMPRESSIVE WARMING IS NOTED AHEAD OF FEATURE. 850MB TEMPS AT KBIS/KABR/KINL HAVE JUMPED FROM -1/-6/-15C RESPECTIVELY AT 00Z TUE TO 11/9/-9C AT 12Z. STRONG WAA HAS YET TO YIELD ANY PCPN. ONLY SOME MID AND HIGH CLOUDS ARE NOTED. AS SHORTWAVE CONTINUES ESE...DON`T ANTICIPATE ANY PCPN TO DEVELOP IN ONGOING STRONG WAA GIVEN OVERALL RELATIVELY DRY ENVIRONMENT SHOWN ON THIS MORNINGS REGIONAL SOUNDINGS. THERE IS JUST ENOUGH LINGERING OVERWATER INSTABILITY TO GENERATE SOME -SHSN OFF THE LAKES UNDER SYNOPTIC FORCING. WIND SHOULD HAVE ENOUGH SOUTHERLY COMPONENT TO WARRANT A MENTION OF -SHSN OVER THE E THIS EVENING... AND ALSO OVER THE KEWEENAW LATER THIS EVENING AND OVER THE NE FCST AREA WED MORNING AS SW WINDS VEER WNW. OTHERWISE...CONCERN AFTER FROPA IS POTENTIAL FOR -FZDZ AS MIDLEVELS SHARPLY DRY WHILE MODELS INSIST THAT A SHALLOW MOIST LAYER (2-3KFT THICK) MATERIALIZES. TEMPS WITHIN THE SHALLOW MOIST LAYER ARE WARMER THAN -10C...SUGGESTING NO ICE NUCLEATION. SATELLITE/UPSTREAM OBS HAVE YET TO SHOW ANY LOW CLOUD DEVELOPMENT. HOWEVER...NOSE OF HIGHER SFC DWPTS WELL INTO THE 20S INTO SRN MANITOBA/ERN ND IS SUPPORTIVE OF A POTENTIAL LOW-CLOUD DECK DEVELOPING AS THE MOISTURE ADVECTS INTO COLDER AIRMASS OVER THE AREA TONIGHT. HAVE THUS INCLUDED A MENTION OF -FZDZ IN THE WNW WIND UPSLOPE AREAS OVER WRN UPPER MI LATE EVENING INTO THE MORNING HRS AND OVER THE NE FCST AREA WED. CONFIDENCE IS LOW. CLOSELY FOLLOWED REGIONAL GEM FOR TEMP TRENDS TONIGHT. SOME AREAS... ESPECIALLY W AND N...WILL SEE MINS EARLY THIS EVENING WITH TEMPS SLOWLY RISING THRU THE NIGHT. MAX TEMPS IN THE UPPER 20S AROUND 30F SHOULD BE THE RULE WED. .LONG TERM /WED NIGHT THROUGH NEXT TUESDAY/... WEAK SHORTWAVE WILL BE SLIDING THROUGH THE NW FLOW AT THE START OF THE PERIOD AND WILL LEAD TO SOME MID CLOUDS OVER MUCH OF THE CWA. LARGE DIFFERENCES IN H850 TEMPS BETWEEN 12Z NAM AND 06Z GFS...WITH THE NAM AROUND -6C AND GFS AROUND -9C OVER THE ERN LK. 12Z GEM AND 00Z ECMWF ARE A LITTLE CLOSER TO THE GFS THAN THE NAM. THESE DIFFERENCES PRODUCE UNCERTAINTY IN LK EFFECT CHANCES AND WILL JUST MENTION FLURRIES OVER THE NW WIND FAVORED AREAS E OF MUNISING WED NIGHT. AS SHORT TERM DISCUSSION MENTIONED...THERE COULD BE SOME DRIZZLE INSTEAD...BUT FELT CHANCES WERE TOO LIMITED TO MENTION. FLATTENING UPPER RIDGE ON THURS WILL BACK H850-500 WINDS TO THE WEST AND PRODUCE BROAD WAA OVER THE UPPER GREAT LKS. WITH MOISTURE STREAMING THROUGH THE UPPER FLOW...THINK THERE WILL BE SOME MID CLOUDS OVER THE AREA THURS INTO THURS NIGHT...BUT DRIER LLVLS WILL LIMIT PCPN EVEN WITH THE INCREASING WAA. SFC LOW DEVELOPING OVER THE CANADIAN ROCKIES ON THURS IN RESPONSE TO SHORTWAVE MOVING THROUGH THE NRN STREAM WILL SHIFT SE TOWARDS LK WINNIPEG BY 00Z FRI. DEEPEST MOISTURE AND STRONGEST WAA WILL OCCUR OVER SRN ONTARIO AND NRN LK SUPERIOR ALONG THE DEVELOPING WARM FRONT THURS AFTN INTO THE EVENING...SO WILL CONTINUE CHANCE PCPN MENTIONS THERE. WITH THE SFC LOW SLIDING THROUGH SRN ONTARIO THURS NIGHT AND FRI...SW HALF OF THE AREA WILL BE UNDER DRY WARM MID LVL AIR /H850 TEMPS RISING TOWARDS 2-3C BY 12Z FRI/. MODELS CONTINUE TO SHOW MOISTURE TRAPPED BELOW THE H900 INVERSION ON THURS NIGHT INTO THE FIRST PART OF FRI...WHICH COULD LEAD TO BROAD LOWER STRATUS AT LEAST ON THURS NIGHT. NOT ENTIRELY CONF ON AMNT/COVERAGE OF LOW CLOUDS...SO WILL CONTINUE PARTLY CLOUDY SKIES OVER THE SW HALF OF THE AREA. INCREASING WINDS...DRIER AIR...AND WEAKENING INVERSION ON FRI SHOULD DIMINISH CLOUD COVERAGE OVER THE SW HALF. THE REST OF THE AREA WILL BE ON THE EDGE OF THE MID CLOUDS FROM THE SYSTEM OVER THE N. WITH AREA IN WARM SECTOR...EXPECT ABOVE NORMAL TEMPERATURES ACROSS THE AREA ON FRI. WILL CONTINUE UPPER 30S FCST...BUT COULD SEE SOME LOWER 40S OVER THE SCNTRL...WHERE THE WARMEST LLVL AIR WILL BE LOCATED. DAYS 4 THROUGH 7 /FRI NIGHT THROUGH NEXT TUESDAY/... THE SFC LOW SHIFTING E THROUGH SERN ONTARIO AT THE START OF THE EXTENDED PERIOD...DROPPING A COLD FRONT WILL SE ACROSS THE CWA FRI NIGHT INTO SAT. DEEP MOISTURE/FORCING CONTINUE TO APPEAR LIMITED AND WILL CONTINUE ONLY LOW END CHANCE POPS WITH THE PASSAGE OF THE FRONT. THE COLD FRONT THAT DROPS ACROSS THE AREA LOOKS TO GET HUNG UP OVER UPPER MI AND NRN WI ON SAT NIGHT DUE TO LIMITED COLD AIR BEHIND TO GIVE IT A PUSH. ADDITIONAL LLVL MOISTURE FROM THE UPPER TROUGH ROTATING THROUGH AND H850 TEMPS GRADUALLY FALLING TOWARDS -14C BY SUN MORNING SHOULD LEAD TO A SLOWLY EXPANDING AREA OF LIGHT LES SAT NIGHT INTO SUN...MAINLY FOR NW WIND LOCATIONS. LACK OF COLD AIR GETTING FORCING INTO THE DGZ IS THE MAIN LIMITING FACTOR...SINCE INVERSION HEIGHTS WILL INITIALLY BE AROUND 6KFT AND PLENTY OF LLVL MOISTURE. DID BUMP POPS UP SOME FOR FAVORED LOCATIONS...BUT KEPT THEM IN THE LOW CHANCE CAT DUE TO LIMITED ACCUM POTENTIAL. HIGH PRESSURE WILL BUILD INTO LK SUPERIOR ON SUN AS UPPER TROUGH SHIFTS E. DRIER AIR AND SUBSIDENCE WILL LEAD TO LOWERING INVERSION HEIGHTS AND SHOULD TAPER OFF LES IN THE EVENING. UPPER GREAT LKS REGION SHIFTS BACK SLIGHTLY NW FLOW ALOFT AS THE RIDGE OVER THE WRN CONUS FLATTENS. THIS WILL ALLOW WARMER H850 TEMPS TO INVADE THE UPPER GREAT LKS REGION AND KEEP THE NRN STREAM WAVES RUNNING ALONG AND JUST N OF THE U.S./CANADIAN BORDER. EXTENDED MODELS CONTINUING TO SHOW WAVE AFFECTING SRN ONTARIO ON MON...WHICH MAY PUSH SOME PCPN OVER THE NE HALF OF THE CWA...OTHERWISE THE FAIRLY QUIET AND ABOVE NORMAL TEMP PATTERN OF WINTER CONTINUES. && .AVIATION /FOR THE 06Z TAF ISSUANCE/... KCMX AND KSAW...EXPECT MVFR CLOUDS AT KCMX TO SPREAD INTO KSAW BY 08Z. DEVELOPING WRLY FLOW COULD ALSO RESULT IN A BRIEF PERIOD OF MIXED -SN AND -FZDZ BTWN 08-11Z AT KCMX. MOSTLY DOWNSLOPE WNW FLOW WILL NOT BE FAVORABLE FOR PCPN AT KSAW. LOOK FOR CONDITIONS TO IMPROVE TO VFR BY LATE MORNING AT BOTH KCMX AND KSAW. KIWD...NOT CONFIDENT ON A MVFR CEILING DVLPG AT KIWD GIVEN LACK OF CLOUDS UPSTREAM AS NOTED ON IR SATELLITE. THUS HAVE ONLY MENTIONED A SCT020 LAYER WHEN THE WIND COMES AROUND TO AN UPSLOPE WRLY DIRECTION AROUND 08Z. EXPECT VFR CONDITIONS TO PERSIST THROUGH THE REST OF THE TAF PD. && .MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/... PERIOD OF S TO SW GALES ARE EXPECTED LATE AFTN/EVENING OVER MUCH OF LAKE SUPERIOR AS PRES GRADIENT TIGHTENS BTWN DEPARTING HIGH PRES AND APPROACHING LOW PRES TROF. HEALTHY AREA OF PRES FALLS (CURRENTLY 8MB/3HR JUST NW OF LAKE SUPERIOR) SHOULD BE SUFFICIENT TO NUDGE WINDS TO GALE FORCE AS PRES FALLS SHIFT EASTWARD THIS EVENING. SW WIND WILL VEER TO THE NW LATER TONIGHT WED...WITH SPEEDS UP TO 25-30 KTS. AS AN AREA OF HIGH PRES MOVES INTO ONTARIO THU...WINDS OVER THE LAKE WILL DIMINISH BLO 20KT. LOOK FOR A STRONGER WESTERLY WIND OF 25-30 KTS TO RETURN FRI FOLLOWING THE PASSAGE OF ANOTHER LOW PRES SYSTEM THRU ONTARIO. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ250-251-266-267. LAKE MICHIGAN... GALE WARNING UNTIL 3 AM EST WEDNESDAY FOR LMZ221-248-250. && $$ UPDATE...VOSS SHORT TERM...ROLFSON LONG TERM...SRF AVIATION...VOSS MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1114 PM EST TUE JAN 3 2012 .UPDATE... GIVEN RECENT IR SATELLITE TRENDS AND FAIRLY DRY LOOK OF 00Z AREA SNDGS...DECIDED TO UPDATE FOR LESS PESSIMISTIC CLOUD CONDITIONS FOR MUCH OF THE CWA FOR THE REST OF TONIGHT. WITH THE EXCEPTION OF THE KEWEENAW PENINSULA (WHERE UPSLOPE FLOW WILL MORE FAVORABLE FOR CLOUDS AND LIGHT MIXED PCPN)...WENT WITH MORE CLEARING OVERNIGHT AND ALSO REMOVED MENTION OF LIGHT SNOW AND PATCHY FZDZ. GENERALLY TRENDED MIN TEMPS DOWNWARD A FEW MORE DEGREES GIVEN LONGER EXPECTED PERIOD OF CLEAR SKIES. LOOK FOR MINS APPROACHING 10F OVER WESTERN INTERIOR COLD SPOT LOCATIONS. && PREV DISCUSSION...ISSUED AT 651 PM EST TUE JAN 3 2012... .SHORT TERM /TONIGHT AND WED/... WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW THE NEXT SHORTWAVE TROF OF INTEREST HEADING SE THRU MANITOBA AND THE DAKOTAS. IMPRESSIVE WARMING IS NOTED AHEAD OF FEATURE. 850MB TEMPS AT KBIS/KABR/KINL HAVE JUMPED FROM -1/-6/-15C RESPECTIVELY AT 00Z TUE TO 11/9/-9C AT 12Z. STRONG WAA HAS YET TO YIELD ANY PCPN. ONLY SOME MID AND HIGH CLOUDS ARE NOTED. AS SHORTWAVE CONTINUES ESE...DON`T ANTICIPATE ANY PCPN TO DEVELOP IN ONGOING STRONG WAA GIVEN OVERALL RELATIVELY DRY ENVIRONMENT SHOWN ON THIS MORNINGS REGIONAL SOUNDINGS. THERE IS JUST ENOUGH LINGERING OVERWATER INSTABILITY TO GENERATE SOME -SHSN OFF THE LAKES UNDER SYNOPTIC FORCING. WIND SHOULD HAVE ENOUGH SOUTHERLY COMPONENT TO WARRANT A MENTION OF -SHSN OVER THE E THIS EVENING... AND ALSO OVER THE KEWEENAW LATER THIS EVENING AND OVER THE NE FCST AREA WED MORNING AS SW WINDS VEER WNW. OTHERWISE...CONCERN AFTER FROPA IS POTENTIAL FOR -FZDZ AS MIDLEVELS SHARPLY DRY WHILE MODELS INSIST THAT A SHALLOW MOIST LAYER (2-3KFT THICK) MATERIALIZES. TEMPS WITHIN THE SHALLOW MOIST LAYER ARE WARMER THAN -10C...SUGGESTING NO ICE NUCLEATION. SATELLITE/UPSTREAM OBS HAVE YET TO SHOW ANY LOW CLOUD DEVELOPMENT. HOWEVER...NOSE OF HIGHER SFC DWPTS WELL INTO THE 20S INTO SRN MANITOBA/ERN ND IS SUPPORTIVE OF A POTENTIAL LOW-CLOUD DECK DEVELOPING AS THE MOISTURE ADVECTS INTO COLDER AIRMASS OVER THE AREA TONIGHT. HAVE THUS INCLUDED A MENTION OF -FZDZ IN THE WNW WIND UPSLOPE AREAS OVER WRN UPPER MI LATE EVENING INTO THE MORNING HRS AND OVER THE NE FCST AREA WED. CONFIDENCE IS LOW. CLOSELY FOLLOWED REGIONAL GEM FOR TEMP TRENDS TONIGHT. SOME AREAS... ESPECIALLY W AND N...WILL SEE MINS EARLY THIS EVENING WITH TEMPS SLOWLY RISING THRU THE NIGHT. MAX TEMPS IN THE UPPER 20S AROUND 30F SHOULD BE THE RULE WED. .LONG TERM /WED NIGHT THROUGH NEXT TUESDAY/... WEAK SHORTWAVE WILL BE SLIDING THROUGH THE NW FLOW AT THE START OF THE PERIOD AND WILL LEAD TO SOME MID CLOUDS OVER MUCH OF THE CWA. LARGE DIFFERENCES IN H850 TEMPS BETWEEN 12Z NAM AND 06Z GFS...WITH THE NAM AROUND -6C AND GFS AROUND -9C OVER THE ERN LK. 12Z GEM AND 00Z ECMWF ARE A LITTLE CLOSER TO THE GFS THAN THE NAM. THESE DIFFERENCES PRODUCE UNCERTAINTY IN LK EFFECT CHANCES AND WILL JUST MENTION FLURRIES OVER THE NW WIND FAVORED AREAS E OF MUNISING WED NIGHT. AS SHORT TERM DISCUSSION MENTIONED...THERE COULD BE SOME DRIZZLE INSTEAD...BUT FELT CHANCES WERE TOO LIMITED TO MENTION. FLATTENING UPPER RIDGE ON THURS WILL BACK H850-500 WINDS TO THE WEST AND PRODUCE BROAD WAA OVER THE UPPER GREAT LKS. WITH MOISTURE STREAMING THROUGH THE UPPER FLOW...THINK THERE WILL BE SOME MID CLOUDS OVER THE AREA THURS INTO THURS NIGHT...BUT DRIER LLVLS WILL LIMIT PCPN EVEN WITH THE INCREASING WAA. SFC LOW DEVELOPING OVER THE CANADIAN ROCKIES ON THURS IN RESPONSE TO SHORTWAVE MOVING THROUGH THE NRN STREAM WILL SHIFT SE TOWARDS LK WINNIPEG BY 00Z FRI. DEEPEST MOISTURE AND STRONGEST WAA WILL OCCUR OVER SRN ONTARIO AND NRN LK SUPERIOR ALONG THE DEVELOPING WARM FRONT THURS AFTN INTO THE EVENING...SO WILL CONTINUE CHANCE PCPN MENTIONS THERE. WITH THE SFC LOW SLIDING THROUGH SRN ONTARIO THURS NIGHT AND FRI...SW HALF OF THE AREA WILL BE UNDER DRY WARM MID LVL AIR /H850 TEMPS RISING TOWARDS 2-3C BY 12Z FRI/. MODELS CONTINUE TO SHOW MOISTURE TRAPPED BELOW THE H900 INVERSION ON THURS NIGHT INTO THE FIRST PART OF FRI...WHICH COULD LEAD TO BROAD LOWER STRATUS AT LEAST ON THURS NIGHT. NOT ENTIRELY CONF ON AMNT/COVERAGE OF LOW CLOUDS...SO WILL CONTINUE PARTLY CLOUDY SKIES OVER THE SW HALF OF THE AREA. INCREASING WINDS...DRIER AIR...AND WEAKENING INVERSION ON FRI SHOULD DIMINISH CLOUD COVERAGE OVER THE SW HALF. THE REST OF THE AREA WILL BE ON THE EDGE OF THE MID CLOUDS FROM THE SYSTEM OVER THE N. WITH AREA IN WARM SECTOR...EXPECT ABOVE NORMAL TEMPERATURES ACROSS THE AREA ON FRI. WILL CONTINUE UPPER 30S FCST...BUT COULD SEE SOME LOWER 40S OVER THE SCNTRL...WHERE THE WARMEST LLVL AIR WILL BE LOCATED. DAYS 4 THROUGH 7 /FRI NIGHT THROUGH NEXT TUESDAY/... THE SFC LOW SHIFTING E THROUGH SERN ONTARIO AT THE START OF THE EXTENDED PERIOD...DROPPING A COLD FRONT WILL SE ACROSS THE CWA FRI NIGHT INTO SAT. DEEP MOISTURE/FORCING CONTINUE TO APPEAR LIMITED AND WILL CONTINUE ONLY LOW END CHANCE POPS WITH THE PASSAGE OF THE FRONT. THE COLD FRONT THAT DROPS ACROSS THE AREA LOOKS TO GET HUNG UP OVER UPPER MI AND NRN WI ON SAT NIGHT DUE TO LIMITED COLD AIR BEHIND TO GIVE IT A PUSH. ADDITIONAL LLVL MOISTURE FROM THE UPPER TROUGH ROTATING THROUGH AND H850 TEMPS GRADUALLY FALLING TOWARDS -14C BY SUN MORNING SHOULD LEAD TO A SLOWLY EXPANDING AREA OF LIGHT LES SAT NIGHT INTO SUN...MAINLY FOR NW WIND LOCATIONS. LACK OF COLD AIR GETTING FORCING INTO THE DGZ IS THE MAIN LIMITING FACTOR...SINCE INVERSION HEIGHTS WILL INITIALLY BE AROUND 6KFT AND PLENTY OF LLVL MOISTURE. DID BUMP POPS UP SOME FOR FAVORED LOCATIONS...BUT KEPT THEM IN THE LOW CHANCE CAT DUE TO LIMITED ACCUM POTENTIAL. HIGH PRESSURE WILL BUILD INTO LK SUPERIOR ON SUN AS UPPER TROUGH SHIFTS E. DRIER AIR AND SUBSIDENCE WILL LEAD TO LOWERING INVERSION HEIGHTS AND SHOULD TAPER OFF LES IN THE EVENING. UPPER GREAT LKS REGION SHIFTS BACK SLIGHTLY NW FLOW ALOFT AS THE RIDGE OVER THE WRN CONUS FLATTENS. THIS WILL ALLOW WARMER H850 TEMPS TO INVADE THE UPPER GREAT LKS REGION AND KEEP THE NRN STREAM WAVES RUNNING ALONG AND JUST N OF THE U.S./CANADIAN BORDER. EXTENDED MODELS CONTINUING TO SHOW WAVE AFFECTING SRN ONTARIO ON MON...WHICH MAY PUSH SOME PCPN OVER THE NE HALF OF THE CWA...OTHERWISE THE FAIRLY QUIET AND ABOVE NORMAL TEMP PATTERN OF WINTER CONTINUES. && .AVIATION /FOR THE 00Z TAF ISSUANCE/... VFR CONDITIONS SHOULD PREVAIL THROUGH THE EVENING HRS AT KIWD/KCMX/KSAW UNDER A RELATIVELY DRY AIRMASS. WITH SFC HIGH PRES EXITING TO THE E...A STRENGTHENING S WIND DEVELOPED THIS AFTERNOON BTWN THE DEPARTING HI AND A DISTURBANCE/AREA OF PRES FALLS PASSING THRU NRN ONTARIO. S WINDS MAY STILL GUST AOA 20 KT INTO EARLY EVENING AT KIWD AND KSAW...BUT OTHERWISE EXPECT WINDS TO DECOUPLE WITH THE POSSIBILITY OF LLWS DEVELOPING. AS THE ONTARIO DISTURBANCE MOVES FARTHER TO THE E TONIGHT...A LOW PRES TROF WILL SWING ACROSS UPPER MI. AS THE FLOW VEERS TO THE WNW...EXPECT LOW CLDS/MVFR CIGS AND PERHAPS SOME -FZDZ OR -SN TO DEVELOP WHERE THIS FLOW UPSLOPES AT KCMX/KIWD. CONFIDENCE IS LOW. DOWNSLOPE NATURE OF THE WIND AT KSAW WILL LIMIT THIS POTENTIAL THERE. EXPECT MVFR CIGS TO LIFT BTWN 16-18Z ON WED AT ALL SITES WITH VFR CONDITIONS FOR THE REST OF WED AFTERNOON. && .MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/... PERIOD OF S TO SW GALES ARE EXPECTED LATE AFTN/EVENING OVER MUCH OF LAKE SUPERIOR AS PRES GRADIENT TIGHTENS BTWN DEPARTING HIGH PRES AND APPROACHING LOW PRES TROF. HEALTHY AREA OF PRES FALLS (CURRENTLY 8MB/3HR JUST NW OF LAKE SUPERIOR) SHOULD BE SUFFICIENT TO NUDGE WINDS TO GALE FORCE AS PRES FALLS SHIFT EASTWARD THIS EVENING. SW WIND WILL VEER TO THE NW LATER TONIGHT WED...WITH SPEEDS UP TO 25-30 KTS. AS AN AREA OF HIGH PRES MOVES INTO ONTARIO THU...WINDS OVER THE LAKE WILL DIMINISH BLO 20KT. LOOK FOR A STRONGER WESTERLY WIND OF 25-30 KTS TO RETURN FRI FOLLOWING THE PASSAGE OF ANOTHER LOW PRES SYSTEM THRU ONTARIO. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ250-251-266-267. LAKE MICHIGAN... GALE WARNING UNTIL 3 AM EST WEDNESDAY FOR LMZ221-248-250. && $$ UPDATE...VOSS SHORT TERM...ROLFSON LONG TERM...SRF AVIATION...VOSS MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
313 AM CST WED JAN 4 2012 .SHORT TERM...TODAY THROUGH FRIDAY NIGHT 313 AM CST WED JAN 4 2012 MAIN FORECAST CONCERNS THIS PACKAGE...ABOVE TO MUCH ABOVE NORMAL TEMPERATURES THROUGH THE PERIOD. DATA ANALYSIS AT 06Z HAD LOW PRESSURE OVER HUDSONS BAY WITH A FRONT/ TROUGH TO THE SOUTH AND SOUTHWEST ACROSS CENTRAL ONT TO NORTHERN WI AND EASTERN KS. ALOFT...LOOP OF WV IMAGERY DEPICTED A MDT SHORTWAVE TROUGH PROGRESSING RATHER QUICKLY SOUTHEAST ACROSS THE UPPER MIDWEST EARLY THIS MORNING. PASSING SHORTWAVE AND PRESSURE FALLS WITH IT KEEPING THE SFC TROUGH/FRONT MOVING STEADILY ACROSS THE AREA EARLY THIS MORNING...WITH A WIND SHIFT TO THE WEST THEN NORTHWEST. TEMPS BEHIND THE FRONT IN THE UPPER 20S-LOW 30S ACROSS THE SOUTHWEST 1/3 OF MN...WITH PRESSURE RISES AND STRONGER WINDS FOR MORE BOUNDARY LAYER MIXING EARLY THIS MORNING. OTHERWISE...TEMPS ELSEWHERE ACROSS MN/IA/WI STILL WELL ABOVE NORMAL FOR EARLY JAN. NO BIG ERRORS NOTED WITH 04.00Z MODEL RUNS...WITH THEIR SOLUTIONS IN THE QUIET/MILD WEATHER PATTERN FOR THE REGION QUITE SIMILAR FOR TONIGHT THU FRI NIGHT. DPROG/DT OF 500MB HGTS AT 04.00Z SHOWED MODEL RUNS OF 02.00Z AND 03.00Z VERIFIED WELL ACROSS NOAM/EASTERN PAC... WITH STRONGER/SLOWER OF EARLIER RUNS BETTER WITH THE SHORTWAVE DROPPING ACROSS THE DAKOTAS/MN. ECMWF WITH THE BETTER RUN-TO-RUN CONSISTENCY AT 04.00Z. GOOD...TIGHTER CONSENSUS AMONG THE MODELS FOR TODAY INTO THU AS HGTS/RISE RIDGING ALOFT BUILDS ACROSS THE REGION. TIGHTER CONSENSUS THU NIGHT/FRI AS HGTS THEN FALL AS STRONGER SHORTWAVE ENERGY TRACK EAST ALONG THE US/CAN BORDER AND ACROSS LK SUPERIOR. TREND DOES FAVOR FASTER OF EARLIER MODELS WITH THE WAVE ACROSS LK SUPERIOR ON FRI. BETTER CONSENSUS ON THE SHORTWAVE DETAILS FRI NIGHT AS ENERGY IN BROAD NORTHWEST FLOW ALOFT DROPS INTO MN/IA. NO MODEL WITH CLEARLY BETTER RUN-TO-RUN CONSISTENCY IN THE TODAY THRU FRI NIGHT PERIOD. CHECK OF OBS VS. MODEL DATA AT 06Z SHOWED ALL WITH DECENT DEPICTIONS OF THE SFC MASS FIELDS OVER CENTRAL NOAM. PER WV IMAGERY...ALL LOOKED TO HAVE GOOD DEPICTIONS OF THE SHORTWAVE DETAILS OVER NOAM/EASTERN PAC. MODELS ACTUALLY DOING A RESPECTABLE JOB WITH THE MILD POST-FRONTAL TEMPS IN THE KFSD/KOMA AREAS EARLY THIS MORNING. NO DETERMINISTIC MODEL FAVORITE AND WITH THE TREND TOWARD A TIGHTER CONSENSUS SOLUTION...FAVORED THE MODEL/ENSEMBLE CONSENSUS. WHAT MINOR MODEL DIFFERENCES THERE ARE APPEAR TO HAVE LITTLE IF ANY IMPACT ON THE SENSIBLE WEATHER THRU FRI NIGHT. SHORT TERM FCST REMAINS GOOD THIS CYCLE. FOR THE SHORT TERM...POST-FRONTAL PRESSURE RISE...INCREASE OF WINDS AND STEADY/SLOWLY RISING TEMPS TO SPREAD ACROSS THE AREA EARLY THIS MORNING. WINDS QUICKLY BECOME WEST THEN SOUTHWEST THRU THE DAY AS THE CENTER OF THE SFC HIGH DROPS INTO THE CENTRAL PLAINS. LOW LEVEL WARM ADVECT RETURNS RATHER QUICKLY TODAY AS THE LOW LEVEL FLOW BECOMES WESTERLY. PRESSURE GRADIENT OVER THE AREA TODAY ON THE WEAK SIDE WITH WINDS MAINLY IN THE 5 TO 10KT RANGE...WHICH WILL LIMIT MIXING. ON THE PLUS SIDE...SUNNY OR MOSTLY SUNNY SKIES EXPECTED ACROSS THE AREA WITH LIMITED MID/HIGH LEVEL MOISTURE IN THE UPPER LEVEL RIDGING AS IT BUILDS EAST. HIGHS TODAY WILL ONCE AGAIN RETURN TO THE 30S FOR MOST LOCATIONS. SFC-850MB WARM ADVECTION CONTINUES TONIGHT/THU WITH 925MB TEMPS IN THE +6C TO +13C RANGE BY 00Z FRI. WINDS TONIGHT A FAVORABLE SOUTHWEST WARMING DIRECTION BUT GRADIENT REMAINS ON THE WEAK SIDE AND SFC WINDS MOSTLY IN THE 5KT RANGE. THE UPPER RIDGE FLATTENS THU AS SHORTWAVE ENERGY MOVING INTO SASKAT/MT AND BEGINS TO SHEAR EASTWARD. THIS WAVE PUSHES AN INCREASE OF 500-300MB MOISTURE THRU THE FLATTENING RIDGE AND ACROSS THE AREA BY THU AFTERNOON. WINDS ON THE LIGHT SIDE AND POTENTIAL FOR AFTERNOON CIRRUS WILL TEMPER THE WARM-UP THU...BUT MOST LOCATIONS SHOULD STILL SEE HIGHS IN THE UPPER 30S TO MID 40S GIVEN THE LACK OF SNOW COVER. THE FAST MOVING SASKAT/MT WAVE MOVES PUSHES A SFC TROUGH/COLD FRONT ACROSS THE AREA THU NIGHT...MUCH LIKE THE ONE THIS MORNING. LOW LEVEL COLD ADVECTION DOES SPREAD ACROSS THE AREA THU NIGHT...BUT AIRMASS BEHIND THE TROUGH/FRONT OF MODIFIED PACIFIC ORIGIN WITH ARCTIC AIR REMAINING WELL NORTH IN CANADA. GRADIENT TIGHTENS A BIT FOR THU NIGHT/FRI WITH MORE WIND FOR BOUNDARY LAYER MIXING. A MILD NIGHT EXPECTED THU NIGHT WITH A WARM START TO FRI MORNING. 925MB TEMPS OVER THE AREA IN THE +2C TO +8C RANGE AT 12Z FRI...ONLY FALLING TO -1C TO +4C BY 00Z SAT. WITH MIXING...THESE TEMPS STILL SUPPORT HIGHS IN THE UPPER 30S TO MID 40S FRI. LOW LEVEL COLD ADVECTION CONTINUES FRI NIGHT BUT SOME WEST/NORTHWEST GRADIENT WINDS KEEP THE BOUNDARY LAYER STIRRED AND THE HIGHS OF THU/FRI WILL MELT MUCH OF WHAT SNOW COVER EXISTS WEST/NORTH OF THE FCST AREA. WITH MINIMAL MOISTURE IN THE 925-600MB LAYER TODAY THRU FRI NIGHT... PRECIP CHANCES ZERO OR NEARLY SO THRU THE PERIOD. NUMERICAL GUIDANCE HIGHS/LOWS QUITE SIMILAR FOR MOST PERIODS AND FAVORED A BLEND OF THEM. IF GRADIENT WINDS END UP A BIT STRONGER THAN EXPECTED THU AND FRI...THE INCREASE OF MECHANICAL MIXING COULD PUSH HIGHS BOTH DAYS UP A CATEGORY FROM THOSE IN THE FCST GRIDS... ESPECIALLY ON THU. .LONG TERM...SATURDAY THROUGH TUESDAY 313 AM CST WED JAN 4 2012 SEASONABLY WARM TEMPS REMAIN THE MAIN CONCERN IN THE DAY 4-7 PERIOD. 04.00Z MEDIUM RANGE MODELS IN REASONABLY GOOD AGREEMENT WITH THE FLOW AND FEATURES TO IMPACT THE REGION SAT THRU TUE. REASONABLE CONSISTENCY WITH THEIR PREVIOUS RUNS AS WELL...WITH CONFIDENCE IN THE LONG-TERM PERIOD AVERAGE TO GOOD. GOOD CONSISTENCY FOR A STRONGER SHORTWAVE TROUGH TO DROP SOUTHEAST ACROSS THE AREA SAT. HOWEVER LOWER LEVEL MOISTURE LOOKS TO BE LIMITED WITH THIS FEATURE WITH LITTLE MORE THAN SOME INCREASE OF MAINLY HIGH CLOUDS WITH ITS PASSAGE. ANOTHER SHORTWAVE TO DROP ACROSS THE REGION SUN...WITH STRONG HGT RISES/WARM ADVECTION TO SPREAD EAST ACROSS THE REGION MON/TUE AS THE WESTERN NOAM RIDGE IS PUSHED EAST. GFS WITH A STRONGER WAVE SUN...AND A BIT MORE SFC-700MB MOISTURE THAN THE OTHER MODELS. GFS WOULD PRODUCE SOME LIGHT PRECIP IN THE FCST AREA SUN WHILE OTHER MODELS AGAIN DO LITTLE MORE THAN INCREASE THE CLOUDS WITH A WEAKER TROUGH PASSAGE. AIRMASS BEHIND THESE WEEKEND FEATURES AGAIN OF MODIFIED PACIFIC ORIGIN...WITH TEMPS SAT/SUN REMAINING ABOVE NORMAL. STRONGER LOW LEVEL WARM ADVECTION MON/TUE WITH PREDOMINANTLY WESTERLY FLOW WOULD AGAIN SEND EARLY JANUARY HIGHS INTO THE MID 30S TO LOWER 40S ON DAYS 6/7. FAVORING A MODEL/ENSEMBLE CONSENSUS ON THE DAY 4-7 DETAILS FOR NOW...MODEL CONSENSUS DATA SET THE SAT THRU TUE FCST GRID SET WELL TRENDED AT THIS TIME. && .AVIATION...THROUGH 06Z THURSDAY 1100 PM CST TUE JAN 3 2012 LATEST SFC OBS AND RUC13 WIND FIELDS CONTINUE TO SUGGEST A FRONTAL PASSAGE AT KRST BETWEEN 08-09Z AND 09-10Z AT KLSE. ONLY SOME HIGH THIN CLOUDS WITH THE SHIFT TO NORTHWEST WINDS...AND LOOK FOR VFR CONDITIONS TO PERSIST INTO WED NIGHT. && .ARX WATCHES/WARNINGS/ADVISORIES... 313 AM CST WED JAN 4 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...RRS LONG TERM... RRS AVIATION.... RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1100 PM CST TUE JAN 3 2012 .SHORT TERM...TONIGHT THROUGH FRIDAY 237 PM CST TUE JAN 3 2012 MAIN FORECAST CONCERNS ARE ON ANY CHANCES FOR PRECIPITATION TONIGHT...THEN THE ABOVE NORMAL TEMPERATURE PATTERN THROUGH FRIDAY. CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED RIDGING PRETTY MUCH DOMINATING THE WESTERN TWO THIRDS OF THE U.S. INTO SOUTHERN CANADA...EXCLUDING A POSITIVELY TILTED SHORTWAVE TROUGH ENTERING THE WESTERN DAKOTAS...WHILE DEEP TROUGHING EXISTED ALONG THE EAST COAST. STRONG WARM ADVECTION HAS BEEN OCCURRING AHEAD OF THE WESTERN DAKOTAS SHORTWAVE...NOTED BY 850MB TEMPS THAT ROSE NEARLY 15C AT ABR AND 8C AT MPX BETWEEN THE 00Z AND 12Z SOUNDINGS. BOTH SOUNDINGS DEPICT A STRONG INVERSION...ESPECIALLY AT ABR...AND IS TO BE EXPECTED THIS TIME OF YEAR WITH SHALLOW COLD AIR MASSES MORE DOMINANT. DAYTIME MIXING THROUGH HIGH CLOUDS AHEAD OF THE SHORTWAVE TROUGH HAS ALLOWED SURFACE TEMPERATURES TO CLIMB INTO THE 20S OVER THE FORECAST AREA...AND INTO THE 30S OVER SOUTHWEST MN INTO WESTERN IOWA. AIR ACROSS THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI RIVER VALLEY WAS QUITE DRY AS WELL...WITH DEWPOINT DEPRESSIONS OFF THE 12Z GRB...MPX AND ABR SOUNDINGS OF 10C OR MORE FROM 950-650MB. AT THE SURFACE...A WARM FRONT WAS LOCATED ALONG THE DAKOTAS/MN BORDER...WITH BREEZY SOUTH WINDS AHEAD OF IT INTO THE FORECAST AREA. BEHIND THE FRONT...READINGS ARE IN THE 40S AND 50S OVER THE DAKOTAS. TONIGHT AND WEDNESDAY...MODELS PROG THE POSITIVELY TILTED SHORTWAVE TROUGH OVER THE WESTERN DAKOTAS TO MOVE SOUTHEAST ACROSS THE FORECAST AREA BETWEEN 06-12Z TONIGHT. IN ITS WAKE...40-70 METER HEIGHT RISES ARE EXPECTED FOR WEDNESDAY AT 500MB WHILE ANOTHER WEAK SHORTWAVE DROPS SOUTHEAST INTO UPPER MICHIGAN. MAIN CONCERN IS WHETHER OR NOT THE SHORTWAVE TROUGH CAN PRODUCE PRECIPITATION TONIGHT. CERTAINLY THERE ARE DECENT 500MB HEIGHT FALLS...60-90 METERS...INDICATIVE OF THE DYNAMIC FORCING. HOWEVER...ISENTROPIC LIFT PLOTS ON 285K-300K SURFACES SHOW LITTLE OR NO LIFT...AS WELL AS PLENTY OF DRY AIR BETWEEN 850-600MB. THEREFORE...NOT EXPECTING ANY PRECIPITATION WITH THE TROUGH. AFTER THIS...THE ONLY CONCERN IS CLOUD COVER. THERE MAY BE SOME LOW CLOUDS IN THE WAKE OF THE TROUGH...BUT MOST OF THESE ARE EXPECTED TO STAY NORTH AND EAST OF THE AREA. ADDITIONAL MID/HIGH CLOUD COVER LOOKS TO COME IN WEDNESDAY AFTERNOON WITH THE NEXT SHORTWAVE...BUT MOST OF THESE CLOUDS SHOULD STAY ALONG OR NORTHEAST OF I-94. REGARDING TEMPERATURES...LOWS TONIGHT WILL END UP MUCH WARMER THAN LAST NIGHT...AIDED BY CLOUD COVER AND THE PASSAGE OF THE WARM FRONT. PREVIOUS FORECAST LOWS SEEM REASONABLE WHICH ONLY SHOW ABOUT A 5 DEGREE TEMPERATURE DROP FROM CURRENT READINGS. GIVEN A WARMER START FOR TOMORROW AND 925MB TEMPS CLIMBING TO -2C TO +1C...HIGHS SHOULD EASILY REACH THE 30S IN MOST LOCATIONS. A FEW LOCATIONS IN NORTHEAST IOWA COULD EVEN REACH 40. WEDNESDAY NIGHT THROUGH FRIDAY...UPPER LEVEL TROUGHING...CURRENTLY SEEN ON WATER VAPOR OVER THE NORTHEAST PACIFIC...IS PROGGED TO MOSTLY EJECT OUT AND DROP DOWN INTO THE NORTHERN PLAINS AND SOUTH CENTRAL CANADA COME FRIDAY IN A POSITIVELY TILTED FORM. AS THE TROUGH HEADS EAST...A SURGE OF PACIFIC AIR ADVECTS EAST WITH IT INTO THE FORECAST AREA...WARMED UP EVEN MORE IN RESPONSE TO DOWNSLOPING OFF THE ROCKIES. 850MB TEMPS CLIMB FROM 0-2C AT 00Z THURSDAY TO AS MUCH AS 8-12C AT 00Z FRIDAY. SOME COOL DOWN IN 850MB TEMPS IS FORECAST FOR FRIDAY WITH READINGS DROPPING FROM 6-10C AT 12Z FRIDAY TO -2 TO +2C BY 00Z SATURDAY...ALL IN RESPONSE TO THE APPROACHING TROUGH. ALTHOUGH A LOT OF THIS WARMING IS TAKING PLACE ALOFT...AGAIN AS TO BE EXPECTED THIS TIME OF YEAR WITH A LOWER SUN ANGLE AND SHORTER DAY LENGTH...THE LACK OF SNOW COVER WILL HELP WITH MIXING. HOW WARM WE ACTUALLY GET IS THE BIG QUESTION. FIRST OFF...THIS TIME PERIOD WILL END UP DRY DUE TO THE SERIOUS LACK OF MOISTURE BELOW 10000 FT AS SEEN ON MODEL SOUNDINGS. NOW REGARDING CLOUD COVER. A STREAM OF MID-HIGH CLOUDS OVER WISCONSIN LATE WEDNESDAY LOOKS TO PUSH SLOWLY EAST THROUGH THURSDAY...IN RESPONSE TO THE BUILDING HEIGHTS ALOFT. ANOTHER SURGE OF MID/HIGH CLOUDS LOOKS TO CROSS THE ENTIRE FORECAST AREA THURSDAY NIGHT...IN THE WESTERLY FLOW AHEAD OF THE SHORTWAVE TROUGH...BUT THESE APPEAR TO SCATTER OUT AND DROP SOUTH FOR FRIDAY. THEREFORE...BOTH THURSDAY AND FRIDAY SHOULD END UP SUNNY/MOSTLY SUNNY. WINDS ARE FORECAST OUT OF GOOD DIRECTIONS FOR WARMING...SOUTHWEST ON THURSDAY AND WEST TO NORTHWEST ON FRIDAY... THOUGH THE SPEEDS ARE 5 TO 10 KT AT BEST. PAST VERIFICATION OF ABOVE NORMAL TEMPERATURE EVENTS SHOWS THAT THE ECMWF TENDS TO DO THE BEST...SO THIS FORECAST LEANS CLOSE TO THE ECMWF GUIDANCE... PARTICULARLY FOR HIGHS. .LONG TERM...FRIDAY NIGHT THROUGH TUESDAY 237 PM CST TUE JAN 3 2012 03.12Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES REMAIN IN VERY GOOD AGREEMENT WITH THE HANDLING OF THE UPPER AIR AND SURFACE PATTERNS THROUGHOUT MUCH OF THE CONUS DURING THE LONG TERM PERIOD. THIS LEADS TO...AT LEAST AT THE MOMENT...ABOVE AVERAGE CONFIDENCE. GENERAL PATTERN SHOWS TROUGHING OVER THE FORECAST AREA SOUTHWESTWARD INTO THE SOUTHWEST U.S. FOR THE WEEKEND. THIS TROUGHING IS CREATED BY THE TROUGH APPROACHING THE AREA ON FRIDAY...A POTENT SHORTWAVE DROPPING SOUTH THROUGH THE ROCKIES...AND THEN ON SUNDAY A SHORTWAVE DROPPING DOWN TOWARD THE AREA. THIS LAST SHORTWAVE COMES DOWN A BUILDING RIDGE OVER THE WESTERN U.S. INTO SOUTHWEST CANADA. WITH THE UPPER TROUGHING OVER THE FORECAST AREA FRIDAY NIGHT THROUGH SUNDAY... COOLER TEMPERATURES CAN BE EXPECTED. 850MB TEMPS FALL TO -6 TO -10C AT 18Z SATURDAY WITH ONLY A SLIGHT WARM UP TO -5 TO -8C AT 18Z SUNDAY. A BLEND OF GUIDANCE SEEMS REASONABLE FOR TEMPERATURES AT THIS TIME. DESPITE THE UPPER TROUGHING MOVING ACROSS...THERE IS VERY LITTLE MOISTURE TO WORK WITH...THEREFORE NO PRECIPITATION IS FORECAST FOR THE WEEKEND AT THIS TIME. FOR MONDAY INTO TUESDAY...A MORE POTENT UPPER TROUGH LOOKS TO MOVE OUT OF THE NORTHEAST PACIFIC INTO SOUTHWEST CANADA...WHICH MAY START DIGGING INTO THE NORTHERN PLAINS LATE TUESDAY. THIS UPPER TROUGH HELPS SHUNT THE BUILDING RIDGING OUT WEST TOWARDS THE FORECAST AREA...BRINGING WITH IT YET ANOTHER SURGE OF PACIFIC AIR. 850MB TEMPS CLIMB RAPIDLY TO AT LEAST 0 TO +6C BY 00Z TUESDAY...IF NOT HIGHER. BY 12Z TUESDAY...THEY ARE SOLIDLY UP TO 6-8C. SOME COOLING COULD OCCUR LATE TUESDAY...DEPENDING ON HOW FAST THAT UPPER TROUGH APPROACHES. IN ANY EVENT...BOTH MONDAY AND TUESDAY LOOK ABOVE TO WELL ABOVE NORMAL AGAIN...ESPECIALLY GIVEN THE LACK OF SNOW COVER. STAYED CLOSER TO THE WARM END OF GUIDANCE FOR HIGHS. PRECIPITATION CHANCES STILL ARE NIL WITH A LACK OF MOISTURE...AND FORCING IN THIS CASE. LOOKING AHEAD...A COLD SHOT OF AIR...SIMILAR TO THE ONE JUST EXPERIENCED YESTERDAY...APPEARS IN THE OFFERING FOR THE MIDDLE AND END OF NEXT WEEK. THIS IS DUE TO THE TROUGHING APPROACHING THE AREA ON TUESDAY DIGGING DOWN TOWARDS THE OHIO VALLEY. RIGHT NOW ANY PRECIPITATION ASSOCIATED WITH THE TROUGH APPEARS TO BE LIGHT...BUT THIS IS STILL 8-10 DAYS OUT. && .AVIATION... 1100 PM CST TUE JAN 3 2012 LATEST SFC OBS AND RUC13 WIND FIELDS CONTINUE TO SUGGEST A FRONTAL PASSAGE AT KRST BETWEEN 08-09Z AND 09-10Z AT KLSE. ONLY SOME HIGH THIN CLOUDS WITH THE SHIFT TO NORTHWEST WINDS...AND LOOK FOR VFR CONDITIONS TO PERSIST INTO WED NIGHT. && .ARX WATCHES/WARNINGS/ADVISORIES... 237 PM CST TUE JAN 3 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM... AJ AVIATION.... RIECK
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1028 PM CST TUE JAN 3 2012 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .SHORT TERM...TONIGHT AND WEDNESDAY. LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE HIGH PRESSURE SHIFTING EAST OVER THE CENTRAL GREAT LAKES THIS AFTERNOON...IN RESPONSE TO MID-LEVEL HEIGHT FALLS OCCURRING OVER THE NORTHERN PLAINS AHEAD OF A SHORTWAVE TROUGH. AHEAD OF THIS TROUGH...MID AND HIGH CLOUDS ARE ON THE INCREASE ACROSS THE REGION. A WARM FRONT LIES FURTHER UPSTREAM ACROSS THE PLAINS BUT THE RAOB NETWORK SHOW AMPLE DRY AIR IN THE MID-LEVELS AND A LACK OF PRECIP. AS THE SHORTWAVE MOVES ACROSS THE REGION TONIGHT...CONCERNS FOCUS ON SMALL POP CHANCES AND TEMPS. TONIGHT...SHORTWAVE TROUGH OVER THE NORTHERN PLAINS WILL SLIDE SOUTHEAST AND BECOME ELONGATED. COMBINED WITH LIFT OVER A H850 WARM FRONT...THE WAVE HAS SOME DECENT FORCING WITH IT. BUT SOUNDINGS UPSTREAM REMAIN PRETTY DRY IN THE MID-LEVELS...AND CANNOT FIND ANY PRECIP REPORTED IN THE OBS OVER SOUTHERN MANITOBA AND SASKATCHEWAN. AS A RESULT...WILL REMOVE THE LIGHT SNOW SHOWER AND FLURRY MENTION. WINDS WILL BE STRENGTHENING OUT OF THE SOUTHWEST AHEAD OF THE SHORTWAVE AND MAY FIND IT DIFFICULT FOR WINDS TO DECOUPLE. WITH THE BKN MID AND HIGH CLOUD COVER...TEMPS WILL BE SIGNIFICANTLY WARMER THAN LAST NITE. LOWS RANGING THROUGH THE TEENS. WEDNESDAY...POTENT 150KT JET STREAK WILL DIVE SOUTHEAST OVER THE WESTERN GREAT LAKES IN THE AFTERNOON. LEFT FRONT QUAD OF THE JET WILL PASS TO THE EAST OF THE REGION...KEEPING ANY UPPER DIVERGENCE FROM CREATING LIGHT PRECIP. WILL STILL SEE INCREASING MID AND HIGH CLOUDS (ABOVE 9KFT OR SO) AFTER A PERIOD OF MOSTLY CLEAR TO PARTLY CLOUDY CONDITIONS IN THE MORNING. TEMPS WILL CONTINUE TO REBOUND TO THE UPPER 20S AND LOWER 30S. .LONG TERM...WEDNESDAY NIGHT THROUGH NEXT TUESDAY. OVERALL MAINLY A QUIET AND RELATIVELY MILD PATTERN DURING THIS PERIOD. UPPER HEIGHTS BUILD WEDNESDAY NIGHT INTO THURSDAY AS A WEAK SURFACE HIGH RIDGE SLIDES OVER. UPPER FLOW BREAKS DOWN BRIEFLY AS A BROAD UPPER TROUGH WORKS OVER THE NORTHERN US REGION. A PERIOD OF WARM AIR ADVECTION AHEAD OF THIS UPPER TROUGH WILL BRING A NEAR STEADY TEMPERATURE TREND TO THE AREA THURSDAY NIGHT. AN ASSOCIATED SURFACE LOW PRESSURE SYSTEM TRACKING OVER THE NORTHERN GREAT LAKES REGION WILL THEN SLIDE A WEAK COLD FRONT OVER THE STATE ON FRIDAY. ANY PCPN WILL BE MINIMAL AND CONFINED WELL NORTH CLOSER TO THE SYSTEM ALONG WITH A PERIOD OF CAA OVER LAKE SUPERIOR. WHILE SURFACE RIDGING SETTLES BACK INTO THE AREA FOR THE WEEKEND WITH THE WESTERN STATES UPPER RIDGE BUILDING...A CONTINUED PARADE OF WEAK MID LEVEL SUBTLE SHORT WAVES ARE PROGGED TO DROP OVER THE AREA FOR THE WEEKEND. AS HAS BEEN THE CASE LATELY...LITTLE MOISTURE AVAILABLE WITH THESE PACIFIC ORIGIN SYSTEMS. MEDIUM RANGE RUNS FLATTEN THE WESTERN RIDGE FOR THE START OF THE NEW WEEK WITH BUILDING UPPER HEIGHTS FOR THE FORECAST AREA. ANOTHER WARMING TREND IS ANTICIPATED WITH THE RETURN SOUTHWEST TO WEST FLOW AS THE MAIN LOW PRESSURE SYSTEM PASSES WELL NORTH OF THE GREAT LAKES REGION. WILL GO ABOVE GUIDANCE NUMBERS THURSDAY NIGHT AS WELL AS NEXT WEEK DUE TO THE WARM AIR ADVECTION. THE AMOUNT OF WARM UP WILL BE TRICKY DUE TO THE LACK OF SNOW COVER WEST TO SOUTHWEST OF THE AREA...BUT STILL NEED TO FACTOR IN A COLD GROUND/INVERSION AND LOW SUN ANGLE...NOT TO MENTION SKY CONDITION. && .AVIATION...FOR 06Z TAF ISSUANCE. FAIRLY QUIET AS JUST HIGH AND SOME MIDDLE CLDS EXPECTED TO WORK ACRS THE RGN AS FRONTAL SYSTEM CROSSES THE AREA. LLWS SHOULD BE DECREASING DURING THE NGT...SO WL ONLY CARRY AT THE START OF THE TAFS. . SKOWRONSKI && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS ALBANY NY
931 AM EST WED JAN 4 2012 .SYNOPSIS... THE HIGH PRESSURE SYSTEM RESPONSIBLE FOR OUR ARCTIC AIR MASS WILL MOVE EAST TODAY...THE AIR MASS WILL BEGIN TO SLOWLY MODERATE THROUGH THE END OF THE WEEK. A FEW WEAK DISTURBANCES WILL PASS THROUGH OVER THE NEXT FEW DAYS...WITH JUST A CHANCE OF MAINLY LIGHT SNOW SHOWERS AND FLURRIES. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... AS OF 930 AM...EXPIRED THE WIND CHILL ADVISORY AS TEMPS ARE WARMING NOW...BUT IT WILL STILL BE COLD TODAY. OTHERWISE...JUST MADE SOME MINOR ADJUSTMENTS TO HOURLY GRIDS BASED ON CURRENT OBS AND TRENDS. CLOUDS INCREASING RAPIDLY FROM CENTRAL NEW YORK ASSOCIATED WITH A WEAK TROF APPROACHING FROM THE WEST. PREVIOUS NEAR TERM DISCUSSION... AS OF 6 AM...HIGH AND MID CLOUDS WERE APPROACHING FROM THE WEST AS THE WARM FRONTAL BOUNDARY BEGINS ITS APPROACH. MINOR TWEAKS TO CURRENT HOURLY GRIDS AS REMAINDER OF THE FORECAST IS IN GOOD SHAPE. SURFACE WARM FRONT WAS APPROACHING FROM THE CENTRAL GREAT LAKES REGION THIS MORNING. UPSTREAM REGIONAL RADAR MOSAIC REVEALS MINIMAL ACTIVITY...HOWEVER...MAIN UPPER SUPPORT PER THE H2O VAPOR LOOP HAS YET TO FULLY INTERACT WITH THIS SURFACE FEATURE. NCEP MODEL SUITE AND HOURLY RUC13 SUPPORT AN OVERALL INCREASE IN LIFT /AGAIN LIKELY DUE TO THE WARM ADVECTIVE PROCESSES/ AND MOISTENING OF THE ATMOSPHERIC COLUMN. QG VERTICAL MOTIONS DO SUGGEST THE POTENTIAL FOR FLURRIES AS THIS WILL BE PLACED IN THE GRIDS/FORECAST. ONCE THE SURFACE WARM FRONTAL BOUNDARY LIFTS NORTHWARD...MARGINAL LAKE INSTABILITY AND FAVORABLE WIND TRAJECTORIES POINT TOWARD LAKE EFFECT/ENHANCED SNOW SHOWERS DOWNWIND OF LAKE ONTARIO INTO PORTIONS OF THE DACKS. LOW LEVEL CONVERGENCE FIELDS INCREASE AS HIRES QPF SUGGEST ACCUMULATIONS WILL BE MINOR. AFTER A VERY CHILLY START TO THE DAY...WE SHOULD REBOUND BACK INTO THE 20S FOR THE MAJORITY OF THE CWFA THIS AFTERNOON. && .SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/... LAKE RESPONSE WILL CONTINUE TONIGHT...YET INVERSION LEVELS ARE LESS THAN IDEAL FOR TALL CONVECTIVE GROWTH AND TOO MUCH SHEAR SEEN IN THE PROFILES. NEVERTHELESS...AS ANOTHER COLD FRONT APPROACHES FROM ONTARIO PROVINCE...THIS WILL ENHANCE THE LOW LEVEL CONVERGENCE OVER LAKE ONTARIO FOR A BAND/S/ OF SNOW TO CONCENTRATE INTO THE DACKS. THIS BAND/S/ WILL MIGRATE SOUTH OVERNIGHT AS THAT COLD FRONT SLIDES SOUTHWARD TOWARD SUNRISE THURSDAY. AS AMPLE LOW LEVEL STRATUS WILL BE IN PLACE ACROSS THE REGION...TEMPERATURES WILL NOT DROP TOO MUCH TO KEEP DIURNAL RANGES RATHER SMALL. ON THURSDAY...COLD FRONT SLIDES SOUTHEAST OF THE CWFA WITH RIDGING REESTABLISHING ITSELF OVER THE EASTERN GREAT LAKES. THIS WILL LIMIT LAKE EFFECT ACTIVITY AS WE WILL KEEP CHANCE POPS FOR PORTIONS OF THE MOHAWK VALLEY...SCHOHARIE VALLEY AND EASTERN CATSKILLS. TEMPERATURES SHOULD REBOUND FURTHER WITH MAINLY LOW-MID 30S FOR THE VALLEY LOCATIONS AND MID-UPR 20S FOR THE HIGHER TERRAIN. UPSTREAM...PACIFIC SYSTEM COMES ASHORE AND MOVES ACROSS SOUTHERN CANADA LATE THURSDAY INTO FRIDAY. THIS WILL AID IN AN INCREASE OF MID LEVEL WARM ADVECTION AND TIGHTENING OF THE BAROCLINIC ZONE OVER THE GREAT LAKES REGION. ISENTROPIC LIFT INCREASES THURSDAY NIGHT WITH THE CHANCE FOR LIGHT SNOW EVOLVING ALONG AND NORTH OF I90 WHICH CONTINUES INTO FRIDAY. AS THERMAL PROFILES CONTINUE TO WARM...PRECIPITATION IS EXPECTED TO MIX WITH RAIN DURING FRIDAY. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THERE IS ACTUALLY A FAIR AMOUNT OF AGREEMENT DURING AT LEAST THE FIRST OF THE EXTENDED PERIOD AMONGST THE GLOBAL FORECAST MODEL (GFS)/CANADIAN METEOROLOGICAL CENTER MODEL (CMC) AND THE EUROPEAN CENTER MID RANGE WEATHER FORECAST (ECMWF). THAT SAID...DUE TO LACK OF ANY STRONG SHORT WAVES UPSTREAM IN THE PACIFIC...AND THE FACT THAT THE SOUTHERN JETSTREAM AND NORTHERN JETSTREAM REMAIN BIFURCATED AS THEY HAVE BEEN MOST OF THIS YOUNG WINTER SEASON...FORECAST CONFIDENCE IS ONLY AT A MEDIUM LEVEL. THE PERIOD STARTS OUT WITH A CLIPPER TYPE STORM PROJECTED TO MOVE NORTH OF THE REGION...POSSIBLY LINGERING SNOW SHOWERS OVER THE NORTHERN HALF OF OUR FORECAST REGION FRIDAY NIGHT. SATURDAY THIS SYSTEM MOVES OFF THE CANADIAN MARITIMES AND IN ITS WAKE...RELATIVELY MILD AIR BY JANUARY STANDARDS...FEATURING H850 AT OR A LITTLE ABOVE 0C...WILL BE OVER THE REGION. THERE COULD BE A FEW LIGHT SHOWERS OR RAIN OR SNOW WELL WEST OF THE CAPITAL REGION AHEAD OF AN INCOMING COLD FRONT. ANY ISOLATED/SCATTERED SHOWER ACTIVITY LOOKS LIGHT. A TRAILING COLD FRONT LOOKS TO MOVE THROUGH SATURDAY NIGHT WHICH BRING A SLIGHT CHANCES OF ADDITIONAL LIGHT SHOWERS OF RAIN OR SNOW ACROSS THE REGION...EXCEPT LOW CHANCES OF SNOW ACROSS THE ELEVATED TERRAIN TO OUR WEST. BY SUNDAY...IT LOOKS AS THIS BOUNDARY WILL LAY DOWN SOMEWHERE TO OUR SOUTH AND STALL. WEAK CANADIAN HIGH PRESSURE ATTEMPTS TO BUILD IN. EARLIER RUNS OF THE ECMWF INDICATE A SOMEWHAT POTENTIALLY POTENT WAVE COULD RIDE UP ALONG THIS BOUNDARY AND BRING A ROUND OF SNOW OR MIXED PRECIPITATION. HOWEVER...THE 00Z ECMWF HAS FALLEN IN LINE WITH THE CMC AND GFS WHICH HAVE BOTH INDICATED ANY WAVE TO BE WEAKER AND FURTHER SOUTH. THE TIMING OF THIS WAVE IS SLOWER WITH THE GFS COMPARED TO THE OTHER MODELS MOVING OFF TO OUR SOUTH MONDAY INSTEAD OF SUNDAY. NEVERTHELESS...THE EUROPEAN ENSEMBLES INDICATE A VARIETY OF SOLUTIONS...NOT SURPRISING THIS FAR OUT AS THERE IS STILL A POTENTIAL FOR ENERGY FROM BOTH THE NORTHERN AND SOUTHERN JETSTREAMS TO PHASE. THIS SCENARIO WILL BE WATCHED BUT FOR NOW ONLY KEEP SLIGHT TO LOW CHANCES SUNDAY INTO MONDAY AS IF NOTHING ELSE...AN NORTHEAST FLOW MIGHT KEEP CLOUDS AND LIGHT SPOTTY PRECIPITATION AROUND. BY TUESDAY...ALL THE MODELS INDICATE WHATEVER SYSTEM IS TO OUR EAST AND WEAK HIGH PRESSURE BUILDS IN. TEMPERATURES LOOK TO RUN A LITTLE ABOVE NORMAL DURING THE EXTENDED PERIOD. SATURDAY LOOKS TO BE MILDEST DAY WITH HIGHS CLIMBING INTO THE 40S MOST PLACES...WITH 30S CONFINED TO THE HIGHEST TERRAIN INCLUDING ALL OF THE ADIRONDACK PARK. THE REMAINDER OF THE DAYS WILL SEE HIGHS RANGING FROM THE 30S TO NEAR 40 VALLEYS AREAS...MID 20S TO LOWER 30S HIGHER TERRAIN. OVERNIGHT LOWS WILL GENERALLY BE IN THE 20S DURING THE EXTENDED PERIODS...TEENS ADIRONDACKS. PRECIPITATION AMOUNTS LOOK TO BE A LITTLE BELOW NORMAL...BUT THAT COULD EASILY CHANGE IF ENERGY FROM THE JETSTREAMS HAS THE OPPORTUNITY TO PHASE AT ANY GIVEN TIME DURING THE EXTENDED PERIOD. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... VFR CONDITIONS TO PREVAIL THROUGH TODAY. THE DAY SHOULD START CLEAR WITH WITH LITTLE OR NO WIND AT ALL TERMINALS. WARM AIR ADVECTION CLOUDS WILL OVERSPREAD THE TERMINALS BY MIDDAY WITH BASES AROUND 12000 FEET. THE LIGHT WIND WILL TURN SOUTHERLY 5-10KTS...WITH SOME HIGHER GUSTS POSSIBLE DURING THE AFTERNOON AT KALB. THE CLOUDS LOOK TO LOWER TO ABOUT A 6000-FOOT BASE DURING THE AFTERNOON. THERE MIGHT BE A FLURRIES AT THAT TIME...BUT WITH VIRTUALLY NO IMPACT EXPECTED TO OPERATIONS...DID NOT EVEN INCLUDE A VCSH AT THIS TIME. THE CLOUDS LOOK TO GRADUALLY THIN LATER TONIGHT. OUTLOOK... TON-FRI...MAINLY VFR. CIG. SCHC SW-. SAT...VFR. NO CIG WX. SUN...MAINLY VFR. SCHC SW-. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE REMAINDER OF THIS WEEK. AN ARCTIC AIR MASS RESIDES OVER THE REGION AT THE MOMENT. COLD TEMPERATURES ALONG WITH BRISK WINDS WILL AID IN THE FORMATION OF ICE ON MANY BODIES OF WATER THIS WEEK. ANY PRECIPITATION THAT FALLS THROUGH SATURDAY WILL BE LIGHT AND IN THE FORM OF MAINLY SNOW. 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...BGM NEAR TERM...BGM/JPV SHORT TERM...BGM LONG TERM...HWJIV AVIATION...HWJIV HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
615 AM EST WED JAN 4 2012 .SYNOPSIS... THE HIGH PRESSURE SYSTEM RESPONSIBLE FOR OUR ARCTIC AIR MASS WILL MOVE EAST TODAY...THE AIR MASS WILL BEGIN TO SLOWLY MODERATE THROUGH THE END OF THE WEEK. A FEW WEAK DISTURBANCES WILL PASS THROUGH OVER THE NEXT FEW DAYS...WITH JUST A CHANCE OF MAINLY LIGHT SNOW SHOWERS AND FLURRIES. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 6 AM...HIGH AND MID CLOUDS WERE APPROACHING FROM THE WEST AS THE WARM FRONTAL BOUNDARY BEGINS ITS APPROACH. MINOR TWEAKS TO CURRENT HOURLY GRIDS AS REMAINDER OF THE FORECAST IS IN GOOD SHAPE. SURFACE WARM FRONT WAS APPROACHING FROM THE CENTRAL GREAT LAKES REGION THIS MORNING. UPSTREAM REGIONAL RADAR MOSAIC REVEALS MINIMAL ACTIVITY...HOWEVER...MAIN UPPER SUPPORT PER THE H2O VAPOR LOOP HAS YET TO FULLY INTERACT WITH THIS SURFACE FEATURE. NCEP MODEL SUITE AND HOURLY RUC13 SUPPORT AN OVERALL INCREASE IN LIFT /AGAIN LIKELY DUE TO THE WARM ADVECTIVE PROCESSES/ AND MOISTENING OF THE ATMOSPHERIC COLUMN. QG VERTICAL MOTIONS DO SUGGEST THE POTENTIAL FOR FLURRIES AS THIS WILL BE PLACED IN THE GRIDS/FORECAST. ONCE THE SURFACE WARM FRONTAL BOUNDARY LIFTS NORTHWARD...MARGINAL LAKE INSTABILITY AND FAVORABLE WIND TRAJECTORIES POINT TOWARD LAKE EFFECT/ENHANCED SNOW SHOWERS DOWNWIND OF LAKE ONTARIO INTO PORTIONS OF THE DACKS. LOW LEVEL CONVERGENCE FIELDS INCREASE AS HIRES QPF SUGGEST ACCUMULATIONS WILL BE MINOR. AFTER A VERY CHILLY START TO THE DAY...WE SHOULD REBOUND BACK INTO THE 20S FOR THE MAJORITY OF THE CWFA THIS AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... LAKE RESPONSE WILL CONTINUE TONIGHT...YET INVERSION LEVELS ARE LESS THAN IDEAL FOR TALL CONVECTIVE GROWTH AND TOO MUCH SHEAR SEEN IN THE PROFILES. NEVERTHELESS...AS ANOTHER COLD FRONT APPROACHES FROM ONTARIO PROVINCE...THIS WILL ENHANCE THE LOW LEVEL CONVERGENCE OVER LAKE ONTARIO FOR A BAND/S/ OF SNOW TO CONCENTRATE INTO THE DACKS. THIS BAND/S/ WILL MIGRATE SOUTH OVERNIGHT AS THAT COLD FRONT SLIDES SOUTHWARD TOWARD SUNRISE THURSDAY. AS AMPLE LOW LEVEL STRATUS WILL BE IN PLACE ACROSS THE REGION...TEMPERATURES WILL NOT DROP TOO MUCH TO KEEP DIURNAL RANGES RATHER SMALL. ON THURSDAY...COLD FRONT SLIDES SOUTHEAST OF THE CWFA WITH RIDGING REESTABLISHING ITSELF OVER THE EASTERN GREAT LAKES. THIS WILL LIMIT LAKE EFFECT ACTIVITY AS WE WILL KEEP CHANCE POPS FOR PORTIONS OF THE MOHAWK VALLEY...SCHOHARIE VALLEY AND EASTERN CATSKILLS. TEMPERATURES SHOULD REBOUND FURTHER WITH MAINLY LOW-MID 30S FOR THE VALLEY LOCATIONS AND MID-UPR 20S FOR THE HIGHER TERRAIN. UPSTREAM...PACIFIC SYSTEM COMES ASHORE AND MOVES ACROSS SOUTHERN CANADA LATE THURSDAY INTO FRIDAY. THIS WILL AID IN AN INCREASE OF MID LEVEL WARM ADVECTION AND TIGHTENING OF THE BAROCLINIC ZONE OVER THE GREAT LAKES REGION. ISENTROPIC LIFT INCREASES THURSDAY NIGHT WITH THE CHANCE FOR LIGHT SNOW EVOLVING ALONG AND NORTH OF I90 WHICH CONTINUES INTO FRIDAY. AS THERMAL PROFILES CONTINUE TO WARM...PRECIPITATION IS EXPECTED TO MIX WITH RAIN DURING FRIDAY. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THERE IS ACTUALLY A FAIR AMOUNT OF AGREEMENT DURING AT LEAST THE FIRST OF THE EXTENDED PERIOD AMONGST THE GLOBAL FORECAST MODEL (GFS)/CANADIAN METEOROLOGICAL CENTER MODEL (CMC) AND THE EUROPEAN CENTER MID RANGE WEATHER FORECAST (ECMWF). THAT SAID...DUE TO LACK OF ANY STRONG SHORT WAVES UPSTREAM IN THE PACIFIC...AND THE FACT THAT THE SOUTHERN JETSTREAM AND NORTHERN JETSTREAM REMAIN BIFURCATED AS THEY HAVE BEEN MOST OF THIS YOUNG WINTER SEASON...FORECAST CONFIDENCE IS ONLY AT A MEDIUM LEVEL. THE PERIOD STARTS OUT WITH A CLIPPER TYPE STORM PROJECTED TO MOVE NORTH OF THE REGION...POSSIBLY LINGERING SNOW SHOWERS OVER THE NORTHERN HALF OF OUR FORECAST REGION FRIDAY NIGHT. SATURDAY THIS SYSTEM MOVES OFF THE CANADIAN MARITIMES AND IN ITS WAKE...RELATIVELY MILD AIR BY JANUARY STANDARDS...FEATURING H850 AT OR A LITTLE ABOVE 0C...WILL BE OVER THE REGION. THERE COULD BE A FEW LIGHT SHOWERS OR RAIN OR SNOW WELL WEST OF THE CAPITAL REGION AHEAD OF AN INCOMING COLD FRONT. ANY ISOLATED/SCATTERED SHOWER ACTIVITY LOOKS LIGHT. A TRAILING COLD FRONT LOOKS TO MOVE THROUGH SATURDAY NIGHT WHICH BRING A SLIGHT CHANCES OF ADDITIONAL LIGHT SHOWERS OF RAIN OR SNOW ACROSS THE REGION...EXCEPT LOW CHANCES OF SNOW ACROSS THE ELEVATED TERRAIN TO OUR WEST. BY SUNDAY...IT LOOKS AS THIS BOUNDARY WILL LAY DOWN SOMEWHERE TO OUR SOUTH AND STALL. WEAK CANADIAN HIGH PRESSURE ATTEMPTS TO BUILD IN. EARLIER RUNS OF THE ECMWF INDICATE A SOMEWHAT POTENTIALLY POTENT WAVE COULD RIDE UP ALONG THIS BOUNDARY AND BRING A ROUND OF SNOW OR MIXED PRECIPITATION. HOWEVER...THE 00Z ECMWF HAS FALLEN IN LINE WITH THE CMC AND GFS WHICH HAVE BOTH INDICATED ANY WAVE TO BE WEAKER AND FURTHER SOUTH. THE TIMING OF THIS WAVE IS SLOWER WITH THE GFS COMPARED TO THE OTHER MODELS MOVING OFF TO OUR SOUTH MONDAY INSTEAD OF SUNDAY. NEVERTHELESS...THE EUROPEAN ENSEMBLES INDICATE A VARIETY OF SOLUTIONS...NOT SURPRISING THIS FAR OUT AS THERE IS STILL A POTENTIAL FOR ENERGY FROM BOTH THE NORTHERN AND SOUTHERN JETSTREAMS TO PHASE. THIS SCENARIO WILL BE WATCHED BUT FOR NOW ONLY KEEP SLIGHT TO LOW CHANCES SUNDAY INTO MONDAY AS IF NOTHING ELSE...AN NORTHEAST FLOW MIGHT KEEP CLOUDS AND LIGHT SPOTTY PRECIPITATION AROUND. BY TUESDAY...ALL THE MODELS INDICATE WHATEVER SYSTEM IS TO OUR EAST AND WEAK HIGH PRESSURE BUILDS IN. TEMPERATURES LOOK TO RUN A LITTLE ABOVE NORMAL DURING THE EXTENDED PERIOD. SATURDAY LOOKS TO BE MILDEST DAY WITH HIGHS CLIMBING INTO THE 40S MOST PLACES...WITH 30S CONFINED TO THE HIGHEST TERRAIN INCLUDING ALL OF THE ADIRONDACK PARK. THE REMAINDER OF THE DAYS WILL SEE HIGHS RANGING FROM THE 30S TO NEAR 40 VALLEYS AREAS...MID 20S TO LOWER 30S HIGHER TERRAIN. OVERNIGHT LOWS WILL GENERALLY BE IN THE 20S DURING THE EXTENDED PERIODS...TEENS ADIRONDACKS. PRECIPITATION AMOUNTS LOOK TO BE A LITTLE BELOW NORMAL...BUT THAT COULD EASILY CHANGE IF ENERGY FROM THE JETSTREAMS HAS THE OPPORTUNITY TO PHASE AT ANY GIVEN TIME DURING THE EXTENDED PERIOD. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... VFR CONDITIONS TO PREVAIL THROUGH TODAY. THE DAY SHOULD START CLEAR WITH WITH LITTLE OR NO WIND AT ALL TERMINALS. WARM AIR ADVECTION CLOUDS WILL OVERSPREAD THE TERMINALS BY MIDDAY WITH BASES AROUND 12000 FEET. THE LIGHT WIND WILL TURN SOUTHERLY 5-10KTS...WITH SOME HIGHER GUSTS POSSIBLE DURING THE AFTERNOON AT KALB. THE CLOUDS LOOK TO LOWER TO ABOUT A 6000-FOOT BASE DURING THE AFTERNOON. THERE MIGHT BE A FLURRIES AT THAT TIME...BUT WITH VIRTUALLY NO IMPACT EXPECTED TO OPERATIONS...DID NOT EVEN INCLUDE A VCSH AT THIS TIME. THE CLOUDS LOOK TO GRADUALLY THIN LATER TONIGHT. OUTLOOK... TON-FRI...MAINLY VFR. CIG. SCHC SW-. SAT...VFR. NO CIG WX. SUN...MAINLY VFR. SCHC SW-. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE REMAINDER OF THIS WEEK. AN ARCTIC AIR MASS RESIDES OVER THE REGION AT THE MOMENT. COLD TEMPERATURES ALONG WITH BRISK WINDS WILL AID IN THE FORMATION OF ICE ON MANY BODIES OF WATER THIS WEEK. ANY PRECIPITATION THAT FALLS THROUGH SATURDAY WILL BE LIGHT AND IN THE FORM OF MAINLY SNOW. 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...WIND CHILL ADVISORY UNTIL 9 AM EST THIS MORNING FOR CTZ001. NY...WIND CHILL ADVISORY UNTIL 9 AM EST THIS MORNING FOR NYZ032-033- 042-058-063-082. MA...WIND CHILL ADVISORY UNTIL 9 AM EST THIS MORNING FOR MAZ001-025. VT...NONE. && $$ SYNOPSIS...BGM NEAR TERM...BGM SHORT TERM...BGM LONG TERM...HWJIV AVIATION...HWJIV HYDROLOGY...BGM FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1019 AM EST WED JAN 4 2012 .SYNOPSIS... A WEAK UPPER LEVEL DISTURBANCE WILL ALLOW FOR AN INCREASE IN CLOUD COVER ACROSS THE AREA TODAY. HIGH PRESSURE WILL WORK INTO THE AREA FOR TONIGHT AND DRY CONDITIONS WILL REMAIN ACROSS THE REGION THROUGH THE REMAINDER OF THE WORK WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WHILE GENERALLY WARMER AIR TO WORK INTO ESPECIALLY SOUTHERN FCST AREA...THE WEAK UPR DISTURBANCE WILL BRING CLOUDS THROUGH THE AREA THROUGH THE DAY. VIRGA HAD BEEN REPORTED AT KIND/KCVG WITH CLOUDS LOWERING A BIT. HRRR BRINGS IN SOME LIGHT SHOWERS BY THE TIME THE DISTURBANCE REACHES SE FCST AREA...BUT LOW LEVELS ARE PRETTY DRY SO AM NOT BRINGING IN ANYTHING OTHER THAN ADJUSTING CLOUDS AND EVEN SOME TEMPS IN THE SOUTH. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS THE FA THROUGH THE SHORT TERM TIME FRAME. THERE WILL BE A WARMING TREND THROUGH THE PERIOD WITH TEMPERATURES ABOVE NORMAL FOR THIS TIME OF THE YEAR. TEMPERATURES WILL REACH UP INTO THE UPPER 40S TO MIDDLE 50S ACROSS THE AREA BY FRIDAY. WITH WARM SW FLOW WENT ON THE WARM SIDE OF GUIDANCE FOR TEMPERATURES. && .LONG TERM /SUNDAY THROUGH TUESDAY/... PRECIPITATION WORKS UP INTO THE AREA FROM THE SOUTH ON SATURDAY. THE ECMWF IS FURTHER NORTH WITH THE PRECIPITATION THAN THE GFS HOWEVER THE LATEST ECMWF HAS COME A LITTLE CLOSER IN LINE WITH THE GFS. WENT CLOSE TO THE ECMWF SOLUTION FOR THE LONG TERM PERIOD. PRECIPITATION WILL MAINLY BE IN THE FORM OF RAIN ON SATURDAY HOWEVER AS COLDER AIR WORKS INTO THE AREA SATURDAY NIGHT THERE WILL BE THE POTENTIAL FOR A FEW SNOW SHOWERS TO OCCUR AS WELL. PRECIPITATION WILL MOVE OUT OF THE FA BY SUNDAY. TEMPERATURES WILL STRUGGLE TO RISE ON SUNDAY WITH HIGHS EXPECTED TO BE IN THE MIDDLE 30S TO THE LOW 40S. ON MONDAY A WEAK UPPER LEVEL DISTURBANCE WILL WORK THROUGH THE FA. MODELS ARE IN GENERAL AGREEMENT WITH BRINGING THIS FEATURE INTO THE AREA. MOISTURE IS LIMITED WITH THIS SYSTEM HOWEVER SOME LIGHT PRECIPITATION WILL BE POSSIBLE MAINLY MONDAY MORNING ACROSS THE FA. HIGH PRESSURE WILL RETURN MONDAY NIGHT INTO TUESDAY ALLOWING FOR DRY CONDITIONS ACROSS THE AREA. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. CONSIDERABLE HIGH CLOUDS WILL REMAIN ACROSS THE REGION. A TROUGH OF LOW PRESSURE WILL MOVE THROUGH AFTER 18Z WHICH WILL CAUSE WINDS TO VEER. THERE MAY BE SOME LOW LEVEL MOISTURE ASSOCIATED WITH THIS BOUNDARY. BUT AT THIS POINT IT APPEARS THAT ANY LOWER CLOUDS WILL BE SCATTERED AT BEST. OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...NOVAK NEAR TERM...JDR SHORT TERM...NOVAK LONG TERM...NOVAK AVIATION...
AREA FORECAST DISCUSSION
NWS ALBANY NY
1253 PM EST WED JAN 4 2012 .SYNOPSIS... THE HIGH PRESSURE SYSTEM RESPONSIBLE FOR OUR ARCTIC AIR MASS WILL START TO MOVE EAST TODAY. THE AIR MASS WILL BEGIN TO MODERATE THROUGH THE END OF THE WEEK. A FEW WEAK DISTURBANCES WILL PASS THROUGH OVER THE NEXT FEW DAYS...WITH JUST A CHANCE OF MAINLY LIGHT SNOW SHOWERS AND FLURRIES. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... AS OF 1245 PM EST...CLOUDS CONTINUE TO INCREASE VIA THE LATEST VISIBLE/IR SATELLITE LOOP OVER THE FCST AREA. A H500 VORT MAX IS APPROACHING FROM NORTH GEORGIAN BAY. WE HAVE SEEN SOME LIGHT PCPN RETURNS ON THE REGIONAL MOSAIC RADAR WEST OF LAKE ONTARIO...AND NEAR THE ST LAWRENCE VALLEY. WE KEEP A SLIGHT CHC-LOW CHC OF SNOW SHOWERS OVER THE WRN DACKS LATE THIS AFTERNOON. THE DRY LOW LEVELS ARE PRECLUDING MUCH IN THE FLURRY ACTIVITY OVER MOST THE REGION. TEMPS ARE RUNNING BEHIND AROUND 1 TO 3 DEGREES IN THE HOURLY TRENDS. WE LOWERED MAX TEMPS ABOUT A CATEGORY EVERYWHERE TO AFTERNOON HIGHS IN THE UPPER TEENS TO L20S IN THE VALLEYS...AND TEENS OVER THE MTNS. TEMPS WILL BE STEADY OR SLOWLY RISE OVERNIGHT...AS THE LOW AND MID LEVEL WARM ADVECTION CONTINUES. PREVIOUS NEAR TERM... AS OF 930 AM...EXPIRED THE WIND CHILL ADVISORY AS TEMPS ARE WARMING NOW...BUT IT WILL STILL BE COLD TODAY. OTHERWISE...JUST MADE SOME MINOR ADJUSTMENTS TO HOURLY GRIDS BASED ON CURRENT OBS AND TRENDS. CLOUDS INCREASING RAPIDLY FROM CENTRAL NEW YORK ASSOCIATED WITH A WEAK TROF APPROACHING FROM THE WEST. PREVIOUS NEAR TERM DISCUSSION... AS OF 6 AM...HIGH AND MID CLOUDS WERE APPROACHING FROM THE WEST AS THE WARM FRONTAL BOUNDARY BEGINS ITS APPROACH. MINOR TWEAKS TO CURRENT HOURLY GRIDS AS REMAINDER OF THE FORECAST IS IN GOOD SHAPE. SURFACE WARM FRONT WAS APPROACHING FROM THE CENTRAL GREAT LAKES REGION THIS MORNING. UPSTREAM REGIONAL RADAR MOSAIC REVEALS MINIMAL ACTIVITY...HOWEVER...MAIN UPPER SUPPORT PER THE H2O VAPOR LOOP HAS YET TO FULLY INTERACT WITH THIS SURFACE FEATURE. NCEP MODEL SUITE AND HOURLY RUC13 SUPPORT AN OVERALL INCREASE IN LIFT /AGAIN LIKELY DUE TO THE WARM ADVECTIVE PROCESSES/ AND MOISTENING OF THE ATMOSPHERIC COLUMN. QG VERTICAL MOTIONS DO SUGGEST THE POTENTIAL FOR FLURRIES AS THIS WILL BE PLACED IN THE GRIDS/FORECAST. ONCE THE SURFACE WARM FRONTAL BOUNDARY LIFTS NORTHWARD...MARGINAL LAKE INSTABILITY AND FAVORABLE WIND TRAJECTORIES POINT TOWARD LAKE EFFECT/ENHANCED SNOW SHOWERS DOWNWIND OF LAKE ONTARIO INTO PORTIONS OF THE DACKS. LOW LEVEL CONVERGENCE FIELDS INCREASE AS HIRES QPF SUGGEST ACCUMULATIONS WILL BE MINOR. AFTER A VERY CHILLY START TO THE DAY...WE SHOULD REBOUND BACK INTO THE 20S FOR THE MAJORITY OF THE CWFA THIS AFTERNOON. && .SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/... LAKE RESPONSE WILL CONTINUE TONIGHT...YET INVERSION LEVELS ARE LESS THAN IDEAL FOR TALL CONVECTIVE GROWTH AND TOO MUCH SHEAR SEEN IN THE PROFILES. NEVERTHELESS...AS ANOTHER COLD FRONT APPROACHES FROM ONTARIO PROVINCE...THIS WILL ENHANCE THE LOW LEVEL CONVERGENCE OVER LAKE ONTARIO FOR A BAND/S/ OF SNOW TO CONCENTRATE INTO THE DACKS. THIS BAND/S/ WILL MIGRATE SOUTH OVERNIGHT AS THAT COLD FRONT SLIDES SOUTHWARD TOWARD SUNRISE THURSDAY. AS AMPLE LOW LEVEL STRATUS WILL BE IN PLACE ACROSS THE REGION...TEMPERATURES WILL NOT DROP TOO MUCH TO KEEP DIURNAL RANGES RATHER SMALL. ON THURSDAY...COLD FRONT SLIDES SOUTHEAST OF THE CWFA WITH RIDGING REESTABLISHING ITSELF OVER THE EASTERN GREAT LAKES. THIS WILL LIMIT LAKE EFFECT ACTIVITY AS WE WILL KEEP CHANCE POPS FOR PORTIONS OF THE MOHAWK VALLEY...SCHOHARIE VALLEY AND EASTERN CATSKILLS. TEMPERATURES SHOULD REBOUND FURTHER WITH MAINLY LOW-MID 30S FOR THE VALLEY LOCATIONS AND MID-UPR 20S FOR THE HIGHER TERRAIN. UPSTREAM...PACIFIC SYSTEM COMES ASHORE AND MOVES ACROSS SOUTHERN CANADA LATE THURSDAY INTO FRIDAY. THIS WILL AID IN AN INCREASE OF MID LEVEL WARM ADVECTION AND TIGHTENING OF THE BAROCLINIC ZONE OVER THE GREAT LAKES REGION. ISENTROPIC LIFT INCREASES THURSDAY NIGHT WITH THE CHANCE FOR LIGHT SNOW EVOLVING ALONG AND NORTH OF I90 WHICH CONTINUES INTO FRIDAY. AS THERMAL PROFILES CONTINUE TO WARM...PRECIPITATION IS EXPECTED TO MIX WITH RAIN DURING FRIDAY. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... THERE IS ACTUALLY A FAIR AMOUNT OF AGREEMENT DURING AT LEAST THE FIRST OF THE EXTENDED PERIOD AMONGST THE GLOBAL FORECAST MODEL (GFS)/CANADIAN METEOROLOGICAL CENTER MODEL (CMC) AND THE EUROPEAN CENTER MID RANGE WEATHER FORECAST (ECMWF). THAT SAID...DUE TO LACK OF ANY STRONG SHORT WAVES UPSTREAM IN THE PACIFIC...AND THE FACT THAT THE SOUTHERN JETSTREAM AND NORTHERN JETSTREAM REMAIN BIFURCATED AS THEY HAVE BEEN MOST OF THIS YOUNG WINTER SEASON...FORECAST CONFIDENCE IS ONLY AT A MEDIUM LEVEL. THE PERIOD STARTS OUT WITH A CLIPPER TYPE STORM PROJECTED TO MOVE NORTH OF THE REGION...POSSIBLY LINGERING SNOW SHOWERS OVER THE NORTHERN HALF OF OUR FORECAST REGION FRIDAY NIGHT. SATURDAY THIS SYSTEM MOVES OFF THE CANADIAN MARITIMES AND IN ITS WAKE...RELATIVELY MILD AIR BY JANUARY STANDARDS...FEATURING H850 AT OR A LITTLE ABOVE 0C...WILL BE OVER THE REGION. THERE COULD BE A FEW LIGHT SHOWERS OR RAIN OR SNOW WELL WEST OF THE CAPITAL REGION AHEAD OF AN INCOMING COLD FRONT. ANY ISOLATED/SCATTERED SHOWER ACTIVITY LOOKS LIGHT. A TRAILING COLD FRONT LOOKS TO MOVE THROUGH SATURDAY NIGHT WHICH BRING A SLIGHT CHANCES OF ADDITIONAL LIGHT SHOWERS OF RAIN OR SNOW ACROSS THE REGION...EXCEPT LOW CHANCES OF SNOW ACROSS THE ELEVATED TERRAIN TO OUR WEST. BY SUNDAY...IT LOOKS AS THIS BOUNDARY WILL LAY DOWN SOMEWHERE TO OUR SOUTH AND STALL. WEAK CANADIAN HIGH PRESSURE ATTEMPTS TO BUILD IN. EARLIER RUNS OF THE ECMWF INDICATE A SOMEWHAT POTENTIALLY POTENT WAVE COULD RIDE UP ALONG THIS BOUNDARY AND BRING A ROUND OF SNOW OR MIXED PRECIPITATION. HOWEVER...THE 00Z ECMWF HAS FALLEN IN LINE WITH THE CMC AND GFS WHICH HAVE BOTH INDICATED ANY WAVE TO BE WEAKER AND FURTHER SOUTH. THE TIMING OF THIS WAVE IS SLOWER WITH THE GFS COMPARED TO THE OTHER MODELS MOVING OFF TO OUR SOUTH MONDAY INSTEAD OF SUNDAY. NEVERTHELESS...THE EUROPEAN ENSEMBLES INDICATE A VARIETY OF SOLUTIONS...NOT SURPRISING THIS FAR OUT AS THERE IS STILL A POTENTIAL FOR ENERGY FROM BOTH THE NORTHERN AND SOUTHERN JETSTREAMS TO PHASE. THIS SCENARIO WILL BE WATCHED BUT FOR NOW ONLY KEEP SLIGHT TO LOW CHANCES SUNDAY INTO MONDAY AS IF NOTHING ELSE...AN NORTHEAST FLOW MIGHT KEEP CLOUDS AND LIGHT SPOTTY PRECIPITATION AROUND. BY TUESDAY...ALL THE MODELS INDICATE WHATEVER SYSTEM IS TO OUR EAST AND WEAK HIGH PRESSURE BUILDS IN. TEMPERATURES LOOK TO RUN A LITTLE ABOVE NORMAL DURING THE EXTENDED PERIOD. SATURDAY LOOKS TO BE MILDEST DAY WITH HIGHS CLIMBING INTO THE 40S MOST PLACES...WITH 30S CONFINED TO THE HIGHEST TERRAIN INCLUDING ALL OF THE ADIRONDACK PARK. THE REMAINDER OF THE DAYS WILL SEE HIGHS RANGING FROM THE 30S TO NEAR 40 VALLEYS AREAS...MID 20S TO LOWER 30S HIGHER TERRAIN. OVERNIGHT LOWS WILL GENERALLY BE IN THE 20S DURING THE EXTENDED PERIODS...TEENS ADIRONDACKS. PRECIPITATION AMOUNTS LOOK TO BE A LITTLE BELOW NORMAL...BUT THAT COULD EASILY CHANGE IF ENERGY FROM THE JETSTREAMS HAS THE OPPORTUNITY TO PHASE AT ANY GIVEN TIME DURING THE EXTENDED PERIOD. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... MID LEVEL CLOUDS WILL CONTINUE TO INCREASE THROUGH THE AFTERNOON AHEAD OF A TROF OF LOW PRESSURE MOVING EASTWARD ACROSS THE GREAT LAKES. CIGS WILL GRADUALLY LOWER AS THE TROF MOVES THROUGH TONIGHT...BUT ARE EXPECTED TO REMAIN IN VFR RANGE. SOME MVFR CIGS ARE POSSIBLE AT KGFL BUT NOT ENOUGH CONFIDENCE TO MENTION IN TAFS. BKN CLOUDS IN VFR RANGE ARE EXPECTED FOR THURSDAY MORNING. WINDS WILL BE SOUTH AROUND 5 KT THIS AFTERNOON...WITH SPEEDS DECREASING TO AROUND 2-5 KT OVERNIGHT. WINDS WILL SHIFT TO THE SOUTHWEST THURSDAY MORNING AT 5-8 KT. OUTLOOK... THU NGT-FRI...MAINLY VFR. SLIGHT CHC -SHSN. SAT...VFR. NO SIG WX. SUN...MAINLY VFR. SLIGHT CHC -SHSN. MON...VFR. NO SIG WX. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE REMAINDER OF THIS WEEK. AN ARCTIC AIR MASS RESIDES OVER THE REGION AT THE MOMENT. COLD TEMPERATURES ALONG WITH BRISK WINDS WILL AID IN THE FORMATION OF ICE ON MANY BODIES OF WATER THIS WEEK. ANY PRECIPITATION THAT FALLS THROUGH SATURDAY WILL BE LIGHT AND IN THE FORM OF MAINLY SNOW. 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...BGM/JPV NEAR TERM...BGM/JPV/WASULA SHORT TERM...BGM LONG TERM...HWJIV AVIATION...JPV HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
1242 PM EST WED JAN 4 2012 .SYNOPSIS... THE HIGH PRESSURE SYSTEM RESPONSIBLE FOR OUR ARCTIC AIR MASS WILL START TO MOVE EAST TODAY. THE AIR MASS WILL BEGIN TO MODERATE THROUGH THE END OF THE WEEK. A FEW WEAK DISTURBANCES WILL PASS THROUGH OVER THE NEXT FEW DAYS...WITH JUST A CHANCE OF MAINLY LIGHT SNOW SHOWERS AND FLURRIES. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... AS OF 930 AM...EXPIRED THE WIND CHILL ADVISORY AS TEMPS ARE WARMING NOW...BUT IT WILL STILL BE COLD TODAY. OTHERWISE...JUST MADE SOME MINOR ADJUSTMENTS TO HOURLY GRIDS BASED ON CURRENT OBS AND TRENDS. CLOUDS INCREASING RAPIDLY FROM CENTRAL NEW YORK ASSOCIATED WITH A WEAK TROF APPROACHING FROM THE WEST. PREVIOUS NEAR TERM DISCUSSION... AS OF 6 AM...HIGH AND MID CLOUDS WERE APPROACHING FROM THE WEST AS THE WARM FRONTAL BOUNDARY BEGINS ITS APPROACH. MINOR TWEAKS TO CURRENT HOURLY GRIDS AS REMAINDER OF THE FORECAST IS IN GOOD SHAPE. SURFACE WARM FRONT WAS APPROACHING FROM THE CENTRAL GREAT LAKES REGION THIS MORNING. UPSTREAM REGIONAL RADAR MOSAIC REVEALS MINIMAL ACTIVITY...HOWEVER...MAIN UPPER SUPPORT PER THE H2O VAPOR LOOP HAS YET TO FULLY INTERACT WITH THIS SURFACE FEATURE. NCEP MODEL SUITE AND HOURLY RUC13 SUPPORT AN OVERALL INCREASE IN LIFT /AGAIN LIKELY DUE TO THE WARM ADVECTIVE PROCESSES/ AND MOISTENING OF THE ATMOSPHERIC COLUMN. QG VERTICAL MOTIONS DO SUGGEST THE POTENTIAL FOR FLURRIES AS THIS WILL BE PLACED IN THE GRIDS/FORECAST. ONCE THE SURFACE WARM FRONTAL BOUNDARY LIFTS NORTHWARD...MARGINAL LAKE INSTABILITY AND FAVORABLE WIND TRAJECTORIES POINT TOWARD LAKE EFFECT/ENHANCED SNOW SHOWERS DOWNWIND OF LAKE ONTARIO INTO PORTIONS OF THE DACKS. LOW LEVEL CONVERGENCE FIELDS INCREASE AS HIRES QPF SUGGEST ACCUMULATIONS WILL BE MINOR. AFTER A VERY CHILLY START TO THE DAY...WE SHOULD REBOUND BACK INTO THE 20S FOR THE MAJORITY OF THE CWFA THIS AFTERNOON. && .SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/... LAKE RESPONSE WILL CONTINUE TONIGHT...YET INVERSION LEVELS ARE LESS THAN IDEAL FOR TALL CONVECTIVE GROWTH AND TOO MUCH SHEAR SEEN IN THE PROFILES. NEVERTHELESS...AS ANOTHER COLD FRONT APPROACHES FROM ONTARIO PROVINCE...THIS WILL ENHANCE THE LOW LEVEL CONVERGENCE OVER LAKE ONTARIO FOR A BAND/S/ OF SNOW TO CONCENTRATE INTO THE DACKS. THIS BAND/S/ WILL MIGRATE SOUTH OVERNIGHT AS THAT COLD FRONT SLIDES SOUTHWARD TOWARD SUNRISE THURSDAY. AS AMPLE LOW LEVEL STRATUS WILL BE IN PLACE ACROSS THE REGION...TEMPERATURES WILL NOT DROP TOO MUCH TO KEEP DIURNAL RANGES RATHER SMALL. ON THURSDAY...COLD FRONT SLIDES SOUTHEAST OF THE CWFA WITH RIDGING REESTABLISHING ITSELF OVER THE EASTERN GREAT LAKES. THIS WILL LIMIT LAKE EFFECT ACTIVITY AS WE WILL KEEP CHANCE POPS FOR PORTIONS OF THE MOHAWK VALLEY...SCHOHARIE VALLEY AND EASTERN CATSKILLS. TEMPERATURES SHOULD REBOUND FURTHER WITH MAINLY LOW-MID 30S FOR THE VALLEY LOCATIONS AND MID-UPR 20S FOR THE HIGHER TERRAIN. UPSTREAM...PACIFIC SYSTEM COMES ASHORE AND MOVES ACROSS SOUTHERN CANADA LATE THURSDAY INTO FRIDAY. THIS WILL AID IN AN INCREASE OF MID LEVEL WARM ADVECTION AND TIGHTENING OF THE BAROCLINIC ZONE OVER THE GREAT LAKES REGION. ISENTROPIC LIFT INCREASES THURSDAY NIGHT WITH THE CHANCE FOR LIGHT SNOW EVOLVING ALONG AND NORTH OF I90 WHICH CONTINUES INTO FRIDAY. AS THERMAL PROFILES CONTINUE TO WARM...PRECIPITATION IS EXPECTED TO MIX WITH RAIN DURING FRIDAY. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THERE IS ACTUALLY A FAIR AMOUNT OF AGREEMENT DURING AT LEAST THE FIRST OF THE EXTENDED PERIOD AMONGST THE GLOBAL FORECAST MODEL (GFS)/CANADIAN METEOROLOGICAL CENTER MODEL (CMC) AND THE EUROPEAN CENTER MID RANGE WEATHER FORECAST (ECMWF). THAT SAID...DUE TO LACK OF ANY STRONG SHORT WAVES UPSTREAM IN THE PACIFIC...AND THE FACT THAT THE SOUTHERN JETSTREAM AND NORTHERN JETSTREAM REMAIN BIFURCATED AS THEY HAVE BEEN MOST OF THIS YOUNG WINTER SEASON...FORECAST CONFIDENCE IS ONLY AT A MEDIUM LEVEL. THE PERIOD STARTS OUT WITH A CLIPPER TYPE STORM PROJECTED TO MOVE NORTH OF THE REGION...POSSIBLY LINGERING SNOW SHOWERS OVER THE NORTHERN HALF OF OUR FORECAST REGION FRIDAY NIGHT. SATURDAY THIS SYSTEM MOVES OFF THE CANADIAN MARITIMES AND IN ITS WAKE...RELATIVELY MILD AIR BY JANUARY STANDARDS...FEATURING H850 AT OR A LITTLE ABOVE 0C...WILL BE OVER THE REGION. THERE COULD BE A FEW LIGHT SHOWERS OR RAIN OR SNOW WELL WEST OF THE CAPITAL REGION AHEAD OF AN INCOMING COLD FRONT. ANY ISOLATED/SCATTERED SHOWER ACTIVITY LOOKS LIGHT. A TRAILING COLD FRONT LOOKS TO MOVE THROUGH SATURDAY NIGHT WHICH BRING A SLIGHT CHANCES OF ADDITIONAL LIGHT SHOWERS OF RAIN OR SNOW ACROSS THE REGION...EXCEPT LOW CHANCES OF SNOW ACROSS THE ELEVATED TERRAIN TO OUR WEST. BY SUNDAY...IT LOOKS AS THIS BOUNDARY WILL LAY DOWN SOMEWHERE TO OUR SOUTH AND STALL. WEAK CANADIAN HIGH PRESSURE ATTEMPTS TO BUILD IN. EARLIER RUNS OF THE ECMWF INDICATE A SOMEWHAT POTENTIALLY POTENT WAVE COULD RIDE UP ALONG THIS BOUNDARY AND BRING A ROUND OF SNOW OR MIXED PRECIPITATION. HOWEVER...THE 00Z ECMWF HAS FALLEN IN LINE WITH THE CMC AND GFS WHICH HAVE BOTH INDICATED ANY WAVE TO BE WEAKER AND FURTHER SOUTH. THE TIMING OF THIS WAVE IS SLOWER WITH THE GFS COMPARED TO THE OTHER MODELS MOVING OFF TO OUR SOUTH MONDAY INSTEAD OF SUNDAY. NEVERTHELESS...THE EUROPEAN ENSEMBLES INDICATE A VARIETY OF SOLUTIONS...NOT SURPRISING THIS FAR OUT AS THERE IS STILL A POTENTIAL FOR ENERGY FROM BOTH THE NORTHERN AND SOUTHERN JETSTREAMS TO PHASE. THIS SCENARIO WILL BE WATCHED BUT FOR NOW ONLY KEEP SLIGHT TO LOW CHANCES SUNDAY INTO MONDAY AS IF NOTHING ELSE...AN NORTHEAST FLOW MIGHT KEEP CLOUDS AND LIGHT SPOTTY PRECIPITATION AROUND. BY TUESDAY...ALL THE MODELS INDICATE WHATEVER SYSTEM IS TO OUR EAST AND WEAK HIGH PRESSURE BUILDS IN. TEMPERATURES LOOK TO RUN A LITTLE ABOVE NORMAL DURING THE EXTENDED PERIOD. SATURDAY LOOKS TO BE MILDEST DAY WITH HIGHS CLIMBING INTO THE 40S MOST PLACES...WITH 30S CONFINED TO THE HIGHEST TERRAIN INCLUDING ALL OF THE ADIRONDACK PARK. THE REMAINDER OF THE DAYS WILL SEE HIGHS RANGING FROM THE 30S TO NEAR 40 VALLEYS AREAS...MID 20S TO LOWER 30S HIGHER TERRAIN. OVERNIGHT LOWS WILL GENERALLY BE IN THE 20S DURING THE EXTENDED PERIODS...TEENS ADIRONDACKS. PRECIPITATION AMOUNTS LOOK TO BE A LITTLE BELOW NORMAL...BUT THAT COULD EASILY CHANGE IF ENERGY FROM THE JETSTREAMS HAS THE OPPORTUNITY TO PHASE AT ANY GIVEN TIME DURING THE EXTENDED PERIOD. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... MID LEVEL CLOUDS WILL CONTINUE TO INCREASE THROUGH THE AFTERNOON AHEAD OF A TROF OF LOW PRESSURE MOVING EASTWARD ACROSS THE GREAT LAKES. CIGS WILL GRADUALLY LOWER AS THE TROF MOVES THROUGH TONIGHT...BUT ARE EXPECTED TO REMAIN IN VFR RANGE. SOME MVFR CIGS ARE POSSIBLE AT KGFL BUT NOT ENOUGH CONFIDENCE TO MENTION IN TAFS. BKN CLOUDS IN VFR RANGE ARE EXPECTED FOR THURSDAY MORNING. WINDS WILL BE SOUTH AROUND 5 KT THIS AFTERNOON...WITH SPEEDS DECREASING TO AROUND 2-5 KT OVERNIGHT. WINDS WILL SHIFT TO THE SOUTHWEST THURSDAY MORNING AT 5-8 KT. OUTLOOK... THU NGT-FRI...MAINLY VFR. SLIGHT CHC -SHSN. SAT...VFR. NO SIG WX. SUN...MAINLY VFR. SLIGHT CHC -SHSN. MON...VFR. NO SIG WX. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE REMAINDER OF THIS WEEK. AN ARCTIC AIR MASS RESIDES OVER THE REGION AT THE MOMENT. COLD TEMPERATURES ALONG WITH BRISK WINDS WILL AID IN THE FORMATION OF ICE ON MANY BODIES OF WATER THIS WEEK. ANY PRECIPITATION THAT FALLS THROUGH SATURDAY WILL BE LIGHT AND IN THE FORM OF MAINLY SNOW. 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...BGM/JPV NEAR TERM...BGM/JPV SHORT TERM...BGM LONG TERM...HWJIV AVIATION...JPV HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
232 PM MST WED JAN 4 2012 .DISCUSSION... 232 PM MST WED JAN 4 2012 EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW PATTERN ACROSS HIGH PLAINS DOMINATED BY LARGE SCALE RIDGE. WITH DRY WEATHER EXPECTED THROUGH THE FORECAST PERIOD...IMMEDIATE FOCUS REMAINS ON NEAR RECORD TEMPS ON THURSDAY. THURSDAY-FRIDAY NIGHT...H5 RIDGE BEGINS TO SHIFT SOUTH BY THURSDAY MORNING...WITH WESTERLY FLOW AND THERMAL TROUGH SUPPORTING WARMER AIR MASS OVER CWA. THURSDAY CONTINUES TO LOOK TO BE VERY WARM...WITH NEAR RECORD HIGHS OVER PARTS OF THE CWA. SNOW PACK CONTINUED TO DETERIORATE TODAY IN THE EXTREME SOUTHERN PART OF CWA...AND IM NOT CONFIDENT IT WILL HAVE MUCH OF AN IMPACT THURSDAY. FOR NOW BEST MIXING STILL APPEARS TO BE OVER NORTHERN AND WESTERN PARTS OF CWA...WHERE TEMPS AROUND 70 ARE POSSIBLE. FURTHER SOUTH...I HAVE TRENDED TEMPS UP SLIGHTLY...THOUGH STILL IN THE LOW TO MID 60S TO ACCOUNT FOR LESSENING IMPACT OF SNOW COVER IN THE SOUTH. WHILE RH VALUES THURSDAY LOOK TO APPROACH CRITICAL LEVELS...WINDS SHOULD REMAIN RELATIVELY LIGHT AND BELOW RED FLAG CRITERIA. DRY COLD FRONT DROPS SOUTH OVER CWA BY FRIDAY MORNING WITH TEMPS DROPPING BACK CLOSER TO SEASONAL LEVELS FRIDAY AND FRIDAY NIGHT...THOUGH THEY STILL APPEAR TO BE WARMER THAN NORMAL WITH HIGHS IN THE UPPER 40S/LOW 50S. SATURDAY-TUESDAY...MOST GUIDANCE CURRENTLY SHOWING CUTOFF LOW DEVELOPING OVER SW CONUS...WITH SPLIT FLOW ACROSS THE PLAINS...WHICH SHOULD RESULT IN DRY FORECAST THROUGH THE EXTENDED. 06Z/12Z GFS CONTINUES TO BE THE OUTLIER SHOWING THIS TROUGH PASSING THROUGH THE PLAINS AS OPEN WAVE. WITH THE GEFS SHOWING SUPPORT FOR THE THE CLOSED SW LOW SOLUTION OF THE ECMWF/GEM...I DECIDED TO DISCOUNT THE WETTER GFS SOLUTION. BIGGER QUESTION IN THE EXTENDED WITH BE TO WHAT EXTENT TEMPS WARM UP MONDAY/TUESDAY. TEMPS IN THE LOW TO MID 50S SEEMS REASONABLE FOR NOW...WITH ECMWF POSSIBLE SUPPORTING TEMPS EVEN A LITTLE WARMER THESE DAYS. DR && .AVIATION... 1036 AM MST WED JAN 4 2012 VFR CONDITIONS CAN BE EXPECTED FOR THE 18Z TAFS. WESTERLY WINDS WILL BE BREEZY DURING THE AFTERNOON WITH SOME GUSTS NEAR 20KT...MAINLY FOR KGLD. OTHERWISE WINDS WILL LIGHTEN AFTER SUNSET. JTL && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED FOR 00Z TAFS
NWS MARQUETTE MI
559 PM EST WED JAN 4 2012 .SYNOPSIS... WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A WRN RIDGE/ERN TROF PATTERN OVER THE CONUS. IN THE NW FLOW OVER THE GREAT LAKES...ONE SHORTWAVE HAS DROPPED SE OF THE AREA WITH ASSOCIATED COLD FRONT NOW INTO LWR MI. BEHIND THE FRONT...LOWER CLOUDS DEVELOPED INTO THE W AND PORTIONS OF THE N AND E TODAY...BUT APPARENTLY NO PCPN HAS OCCURRED. RECENTLY...THE LOWER CLOUDS APPEAR TO BE SCATTERING OUT OF THE W. NEXT SHORTWAVE OF INTEREST IS APPROACHING BRITISH COLUMBIA. && .SHORT TERM /TONIGHT AND THU/... A QUIET NIGHT IS EXPECTED TONIGHT. SMALL BUBBLE OF HIGH PRES WILL SETTLE SE TO A POSITION JUST N OF LAKE SUPERIOR BY SUNRISE THU. 850MB TEMPS HIGHER THAN -10C WILL BE TOO WARM TO SUPPPORT LES. HOWEVER...THE REGIONAL GEM/ECMWF INDICATE 850MB TEMPS SLIPPING TOWARD -12C OVER FAR ERN LAKE SUPERIOR OVERNIGHT. IF SO...THERE COULD BE SOME FLURRIES LATE OVER THE ERN FCST AREA AS LOW-LEVEL WINDS VEER MORE NORTHERLY. TO THE W...WINDS WILL DIMINISH TO CALM...AND IT APPEARS THERE MAY NOT BE MUCH IN THE WAY OF CLOUD COVER FOR A PORTION OF THE NIGHT. HAVE THUS FAVORED THE LOWER SIDE OF GUIDANCE (TEMPS FALLING TOWARD 10F) AS THERE SHOULD BE AN OPPORTUNITY FOR A PERIOD OF DECENT RADIATIONAL COOLING. SHORTWAVE APPROACHING BRITISH COLUMBIA MOVES TO SCNTRL CANADA THU. AHEAD OF FEATURE...STRONG WAA PATTERN DEVELOPS INTO THE UPPER LAKES...AND MODELS DEPICT A SHARPENING 850MB WARM FRONT PUSHING INTO THE AREA. WITH FRONT SHARPENING AS IT SHIFTS E...ISENTROPIC ASCENT PER 290/295K SFCS BECOMES STRONGER TO THE E OF THE FCST AREA. SO... FOR NOW...RETAINED SLIGHT CHC POPS ONLY ACROSS THE KEWEENAW AND E OF MUNISING TO MANISTIQUE WITH HIGHER POPS OVER LAKE SUPERIOR. IT WILL BE A WARM DAY FOR JAN STANDARDS...ESPECIALLY OVER THE W WHERE GUIDANCE VALUES NEARING 40F LOOK REASONABLE GIVEN THE WARMTH SPREADING OUT ACROSS THE DAKOTAS THIS AFTN. TEMPS SHOULD TOP OUT AROUND 30F/LWR 30S OVER THE E. .LONG TERM /THURSDAY NIGHT THROUGH NEXT WEDNESDAY/... TRANSITION FM NW FLOW ALOFT TO MORE ZONAL FLOW BY FRIDAY ALLOWS LOW PRESSURE TROUGH TO STREAK ACROSS MANITOBA/ONTARIO THURSDAY EVENING. WARM FRONT BRIEFLY WILL PUSH ACROSS UPR MI...BUT SINCE CYCLONIC SIDE OF JET AND H85-H7 FRONTOGENESIS STAY OVR ONTARIO...EXPECT MAINLY DRY WX OVR CWA THURSDAY NIGHT. AS SFC LOW MOVES TOWARD SOUTHERN QUEBEC ON FRIDAY MORNING...A SFC TROUGH SHOULD WORK ACROSS UPR MICHIGAN. GFS AND NAM SHOW INCREASING MOISTURE BLO H9...MAINLY OVR THE WEST HALF OF THE CWA...BUT NOT A WHOLE LOT OF UVM IN THAT MOIST LAYER. WINDS COULD SUPPORT ADDITIONAL UPSLOPE LIFT OVR HIGHER TERRAIN OF WEST AND NORTHWEST CWA...BUT SINCE TEMPS IN MOIST LAYER ARE MUCH WARMER THAN -8C THE CHANCE OF ICE WITHIN THE CLOUD IS SLIM. PERHAPS THERE COULD BE SOME DRIZZLE...BUT SFC DWPNT DEPRESSIONS LOOK TOO HIGH TO SUPPORT PUTTING THAT IN FCST. WILL RUN WITH A MAINLY CLOUDY BUT DRY FCST FOR NOW. AS PREVIOUS SHIFT DID...WENT WITH NON-DIURNAL TEMP TREND THURSDAY NIGHT INTO FRIDAY. READINGS ON FRIDAY MOST AREAS WILL BE ABOVE FREEZING...THOUGH TEMPS IN THE WEST COULD BE TEMPERED BY THE INCREASED CLOUD COVER. BETTER PUSH OF COOLER AIR AT H85 OF AROUND -10C ARRIVES FRIDAY NIGHT. COLD AIR ADVECTION AND DEEPENING MOISTURE/CONVERGENCE THROUGH H85 SHOULD ALLOW FOR LGT SNOW TO DEVELOP...HELPED ALONG BY LAKE SUPERIOR SOMEWHAT. LOW CHANCE POPS OVER NORTHERN HALF OF CWA SEEM ON TRACK...HIGHEST IN AREAS FAVORED BY NW WINDS. REGIME FOR LGT LK EFFECT SNOW SHOWERS LINGERS THROUGH MUCH OF SATURDAY. DAYS 4-7...SPLIT FLOW IS FCST TO RETURN IN UPPER LEVELS BY EARLY NEXT WEEK AS UPR LOW DEVELOPS OVER SW CONUS WHILE NORTHERN STREAM BECOMES MORE ZONAL. BY MID-LATE NEXT WEEK THOUGH EXTENDED MODELS AND ENSEMBLES INDICATE DEEPER TROUGHING/COLDER AIRMASS WILL BEGIN TO AFFECT MIDDLE CONUS...INCLUDING THE GREAT LAKES. INITIALLY...ANOTHER WEAK COLD FRONT SLIDING THROUGH SATURDAY NIGHT LEADS TO CHANCES FOR MORE LGT LK EFFECT INTO SUNDAY. BLYR WINDS START OUT NNW SATURDAY EVENING THEN BACK MORE WNW BY SUNDAY. GFS/ECMWF BOTH INDICATE SUFFICIENT LOW-LEVEL MOISTURE TO SUPPORT LK EFFECT SNOW SHOWERS. FCST SOUNDINGS FM GFS INDICATE MAJORITY OF MOISTURE STAYS BLO DGZ WHICH KEEPS RATIOS ON THE LOWER SIDE OF 20:1. LGT ACCUMS POSSIBLE BUT SHOULD NOT BE TOO MUCH SNOW GIVEN MARGINAL OVERWATER INSTABILITY. ZONAL FLOW AND WARM AIR ADVECTIONS TAKES HOLD BY MONDAY. MID CLOUDS MAKE APPEARANCE GIVEN THE WARM AIR ADVECTION AND SFC LOW SLIDING BY ACROSS NORTHERN ONTARIO. WEAK FRONT TIED TO LOW FCST TO MOVE ACROSS UPR LAKES LATER MONDAY INTO TUESDAY. NOT ENOUGH MOISTURE TO JUSTIFY MUCH PRECIPITATION THOUGH. IF THERE IS MUCH PRECIPITATION WILL HAVE TO CONSIDER POSSIBILITY OF MIXED PRECIPITATION AS H85 TEMPS SURGE WELL ABOVE ZERO AHEAD OF PRIMARY COLD FRONT ARRIVING LATER WEDNESDAY. SOUNDINGS FM GFS DO INDICATE THAT EVAPORATIVE COOLING WOULD BRING WET BULB TEMP AOB ZERO THROUGH LOWEST 5KFT. FOR NOW...TOUGH TO GET TOO CARRIED AWAY FM FINE DETAILS SO INCLUDED MENTION OF BROADBRUSHED MENTION OF RAIN/SNOW FOR PTYPE MONDAY NIGHT/TUESDAY/TUESDAY NIGHT. BEST CHANCE FOR PRECIP WILL BE TUESDAY NIGHT. BASED ON SFC TEMPS BLO FREEZING...CAN NOT RULE OUT FREEZING RAIN EITHER. THOUGH AS WE GET CLOSER TO THIS TIME FRAME SUSPECT SFC TEMPS FM MODELS MAY TREND WARMER...ESPECIALLY OUT AHEAD OF THE COLD FRONT TUESDAY NIGHT. SOME AGREEMENT FM THE GFS/ECMWF THAT LARGER SCALE SYSTEM MAY AFFECT UPR LAKES BY NEXT WEDNESDAY IN ADVANCE OF CHANGE TO COOLER WEATHER PATTERN. PTYPE WOULD BE MAINLY SNOW BASED ON COOLING H85 TEMPS. MAIN QUESTION IS HOW MUCH PHASING OCCURS BTWN NORTHERN STREAM SHORTWAVE TROUGH MOVING THROUGH AT THAT TIME AND THE SOUTHERN STREAM WAVE SLIDING FM SW CONUS INTO SOUTHERN PLAINS AND EVENTUALLY OHIO VALLEY. RECENT RUN OF THE ECMWF WAS MOST EMPHATIC WITH PHASING WHILE PREVIOUS ECMWF RUNS AND RUNS OF THE GFS WERE MORE SEPARATE. EVEN SO...00Z GFS WOULD HAVE WIDESPREAD SNOW ACROSS UPR LAKES ON WEDNESDAY DUE TO INCREASING UPR JET DIVERGENCE/MID-LEVEL FRONTOGENESIS AHEAD OF THE DEEPENING NORTHERN STREAM TROUGH. 12Z GFS TRENDED WEAKER WITH THIS LEAD WAVE OF SNOW FOR WEDNESDAY THOUGH. 12Z ECMWF HAS ALSO TRENDED MORE SEPARATE WITH BOTH STREAMS. SO PROBABLY WILL BE AT LEAST SOME LIGHT SNOW AROUND ON WEDNESDAY WITH STRONG COLD FRONT COMING THROUGH LATER WEDNESDAY INTO THURSDAY LEADING TO BLO NORMAL TEMPS AND LAKE EFFECT SNOWS FOR THE LATER PORTION OF NEXT WEEK FOR MAINLY NORTHWEST WIND SNOW BELTS. && .AVIATION /FOR THE 00Z TAF ISSUANCE/... VFR CONDITIONS WILL CONTINUE THRU THE END OF THE FCST PERIOD AT KIWD. WILL GET A BIT GUSTY IN THE AFTERNOON. PERSISTENT W TO NW UPSLOPE FLOW SHOULD RESULT IN MVFR CIGS LINGERING AT KCMX THRU TONIGHT. AS WINDS BECOME SSE THU MORNING...EXPECT LOW CLOUDS TO EXIT WITH RETURN TO VFR CONDITIONS. AT KSAW...THERE MAY BE OCNL PERIODS OF MVFR CIGS THIS EVENING...BUT OVERALL DOWNSLOPE COMPONENT TO THE WIND SHOULD WORK TO KEEP LOWER CLOUDS MOSTLY SCT. VFR CONDITIONS SHOULD PREVAIL THROUGH THE FORECAST PERIOD. WILL GET GUSTY IN THE AFTERNOON AS WELL. && .MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/... WINDS WILL DIMINISH TO UNDER 20KT FROM W TO E TONIGHT INTO THU MORNING AS SMALL AREA OF SFC HIGH PRES SETTLES SE TO JUST N OF LAKE SUPERIOR BY MORNING. LIGHTER WINDS WILL BE SHORT-LIVED AS SOUTHERLY WINDS WILL QUICKLY RAMP UP TO 20-30KT IN THE AFTN DUE TO HEALTHY PRES FALLS SHIFTING E INTO NRN ONTARIO AHEAD OF THE NEXT LOW PRES AREA MOVING E ACROSS SCNTRL CANADA. MAGNITUDE OF PRES FALLS SUGGESTS A SHORT PERIOD OF GALES MAY OCCUR THU EVENING. SINCE MODERATING AIRMASS/INCREASING STABILITY WILL WORK TO LIMIT STRONGER WINDS... HAVE OPTED TO HOLD OFF FROM ISSUING A GALE WATCH AT THIS POINT. 20-30KT WINDS WILL LINGER INTO FRI AS THE LOW PRES AREA TRACKS E JUST TO THE N OF LAKE SUPERIOR. LIGHTER WINDS WILL RETURN FOR SAT/SUN AS THE PRES GRADIENT SLACKENS WITH THE APPROACH OF HIGH PRES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SYNOPSIS...ROLFSON SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...07 MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
400 PM EST WED JAN 4 2012 .SYNOPSIS... WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A WRN RIDGE/ERN TROF PATTERN OVER THE CONUS. IN THE NW FLOW OVER THE GREAT LAKES...ONE SHORTWAVE HAS DROPPED SE OF THE AREA WITH ASSOCIATED COLD FRONT NOW INTO LWR MI. BEHIND THE FRONT...LOWER CLOUDS DEVELOPED INTO THE W AND PORTIONS OF THE N AND E TODAY...BUT APPARENTLY NO PCPN HAS OCCURRED. RECENTLY...THE LOWER CLOUDS APPEAR TO BE SCATTERING OUT OF THE W. NEXT SHORTWAVE OF INTEREST IS APPROACHING BRITISH COLUMBIA. && .SHORT TERM /TONIGHT AND THU/... A QUIET NIGHT IS EXPECTED TONIGHT. SMALL BUBBLE OF HIGH PRES WILL SETTLE SE TO A POSITION JUST N OF LAKE SUPERIOR BY SUNRISE THU. 850MB TEMPS HIGHER THAN -10C WILL BE TOO WARM TO SUPPPORT LES. HOWEVER...THE REGIONAL GEM/ECMWF INDICATE 850MB TEMPS SLIPPING TOWARD -12C OVER FAR ERN LAKE SUPERIOR OVERNIGHT. IF SO...THERE COULD BE SOME FLURRIES LATE OVER THE ERN FCST AREA AS LOW-LEVEL WINDS VEER MORE NORTHERLY. TO THE W...WINDS WILL DIMINISH TO CALM...AND IT APPEARS THERE MAY NOT BE MUCH IN THE WAY OF CLOUD COVER FOR A PORTION OF THE NIGHT. HAVE THUS FAVORED THE LOWER SIDE OF GUIDANCE (TEMPS FALLING TOWARD 10F) AS THERE SHOULD BE AN OPPORTUNITY FOR A PERIOD OF DECENT RADIATIONAL COOLING. SHORTWAVE APPROACHING BRITISH COLUMBIA MOVES TO SCNTRL CANADA THU. AHEAD OF FEATURE...STRONG WAA PATTERN DEVELOPS INTO THE UPPER LAKES...AND MODELS DEPICT A SHARPENING 850MB WARM FRONT PUSHING INTO THE AREA. WITH FRONT SHARPENING AS IT SHIFTS E...ISENTROPIC ASCENT PER 290/295K SFCS BECOMES STRONGER TO THE E OF THE FCST AREA. SO... FOR NOW...RETAINED SLIGHT CHC POPS ONLY ACROSS THE KEWEENAW AND E OF MUNISING TO MANISTIQUE WITH HIGHER POPS OVER LAKE SUPERIOR. IT WILL BE A WARM DAY FOR JAN STANDARDS...ESPECIALLY OVER THE W WHERE GUIDANCE VALUES NEARING 40F LOOK REASONABLE GIVEN THE WARMTH SPREADING OUT ACROSS THE DAKOTAS THIS AFTN. TEMPS SHOULD TOP OUT AROUND 30F/LWR 30S OVER THE E. .LONG TERM /THURSDAY NIGHT THROUGH NEXT WEDNESDAY/... TRANSITION FM NW FLOW ALOFT TO MORE ZONAL FLOW BY FRIDAY ALLOWS LOW PRESSURE TROUGH TO STREAK ACROSS MANITOBA/ONTARIO THURSDAY EVENING. WARM FRONT BRIEFLY WILL PUSH ACROSS UPR MI...BUT SINCE CYCLONIC SIDE OF JET AND H85-H7 FRONTOGENESIS STAY OVR ONTARIO...EXPECT MAINLY DRY WX OVR CWA THURSDAY NIGHT. AS SFC LOW MOVES TOWARD SOUTHERN QUEBEC ON FRIDAY MORNING...A SFC TROUGH SHOULD WORK ACROSS UPR MICHIGAN. GFS AND NAM SHOW INCREASING MOISTURE BLO H9...MAINLY OVR THE WEST HALF OF THE CWA...BUT NOT A WHOLE LOT OF UVM IN THAT MOIST LAYER. WINDS COULD SUPPORT ADDITIONAL UPSLOPE LIFT OVR HIGHER TERRAIN OF WEST AND NORTHWEST CWA...BUT SINCE TEMPS IN MOIST LAYER ARE MUCH WARMER THAN -8C THE CHANCE OF ICE WITHIN THE CLOUD IS SLIM. PERHAPS THERE COULD BE SOME DRIZZLE...BUT SFC DWPNT DEPRESSIONS LOOK TOO HIGH TO SUPPORT PUTTING THAT IN FCST. WILL RUN WITH A MAINLY CLOUDY BUT DRY FCST FOR NOW. AS PREVIOUS SHIFT DID...WENT WITH NON-DIURNAL TEMP TREND THURSDAY NIGHT INTO FRIDAY. READINGS ON FRIDAY MOST AREAS WILL BE ABOVE FREEZING...THOUGH TEMPS IN THE WEST COULD BE TEMPERED BY THE INCREASED CLOUD COVER. BETTER PUSH OF COOLER AIR AT H85 OF AROUND -10C ARRIVES FRIDAY NIGHT. COLD AIR ADVECTION AND DEEPENING MOISTURE/CONVERGENCE THROUGH H85 SHOULD ALLOW FOR LGT SNOW TO DEVELOP...HELPED ALONG BY LAKE SUPERIOR SOMEWHAT. LOW CHANCE POPS OVER NORTHERN HALF OF CWA SEEM ON TRACK...HIGHEST IN AREAS FAVORED BY NW WINDS. REGIME FOR LGT LK EFFECT SNOW SHOWERS LINGERS THROUGH MUCH OF SATURDAY. DAYS 4-7...SPLIT FLOW IS FCST TO RETURN IN UPPER LEVELS BY EARLY NEXT WEEK AS UPR LOW DEVELOPS OVER SW CONUS WHILE NORTHERN STREAM BECOMES MORE ZONAL. BY MID-LATE NEXT WEEK THOUGH EXTENDED MODELS AND ENSEMBLES INDICATE DEEPER TROUGHING/COLDER AIRMASS WILL BEGIN TO AFFECT MIDDLE CONUS...INCLUDING THE GREAT LAKES. INITIALLY...ANOTHER WEAK COLD FRONT SLIDING THROUGH SATURDAY NIGHT LEADS TO CHANCES FOR MORE LGT LK EFFECT INTO SUNDAY. BLYR WINDS START OUT NNW SATURDAY EVENING THEN BACK MORE WNW BY SUNDAY. GFS/ECMWF BOTH INDICATE SUFFICIENT LOW-LEVEL MOISTURE TO SUPPORT LK EFFECT SNOW SHOWERS. FCST SOUNDINGS FM GFS INDICATE MAJORITY OF MOISTURE STAYS BLO DGZ WHICH KEEPS RATIOS ON THE LOWER SIDE OF 20:1. LGT ACCUMS POSSIBLE BUT SHOULD NOT BE TOO MUCH SNOW GIVEN MARGINAL OVERWATER INSTABILITY. ZONAL FLOW AND WARM AIR ADVECTIONS TAKES HOLD BY MONDAY. MID CLOUDS MAKE APPEARANCE GIVEN THE WARM AIR ADVECTION AND SFC LOW SLIDING BY ACROSS NORTHERN ONTARIO. WEAK FRONT TIED TO LOW FCST TO MOVE ACROSS UPR LAKES LATER MONDAY INTO TUESDAY. NOT ENOUGH MOISTURE TO JUSTIFY MUCH PRECIPITATION THOUGH. IF THERE IS MUCH PRECIPITATION WILL HAVE TO CONSIDER POSSIBILITY OF MIXED PRECIPITATION AS H85 TEMPS SURGE WELL ABOVE ZERO AHEAD OF PRIMARY COLD FRONT ARRIVING LATER WEDNESDAY. SOUNDINGS FM GFS DO INDICATE THAT EVAPORATIVE COOLING WOULD BRING WET BULB TEMP AOB ZERO THROUGH LOWEST 5KFT. FOR NOW...TOUGH TO GET TOO CARRIED AWAY FM FINE DETAILS SO INCLUDED MENTION OF BROADBRUSHED MENTION OF RAIN/SNOW FOR PTYPE MONDAY NIGHT/TUESDAY/TUESDAY NIGHT. BEST CHANCE FOR PRECIP WILL BE TUESDAY NIGHT. BASED ON SFC TEMPS BLO FREEZING...CAN NOT RULE OUT FREEZING RAIN EITHER. THOUGH AS WE GET CLOSER TO THIS TIME FRAME SUSPECT SFC TEMPS FM MODELS MAY TREND WARMER...ESPECIALLY OUT AHEAD OF THE COLD FRONT TUESDAY NIGHT. SOME AGREEMENT FM THE GFS/ECMWF THAT LARGER SCALE SYSTEM MAY AFFECT UPR LAKES BY NEXT WEDNESDAY IN ADVANCE OF CHANGE TO COOLER WEATHER PATTERN. PTYPE WOULD BE MAINLY SNOW BASED ON COOLING H85 TEMPS. MAIN QUESTION IS HOW MUCH PHASING OCCURS BTWN NORTHERN STREAM SHORTWAVE TROUGH MOVING THROUGH AT THAT TIME AND THE SOUTHERN STREAM WAVE SLIDING FM SW CONUS INTO SOUTHERN PLAINS AND EVENTUALLY OHIO VALLEY. RECENT RUN OF THE ECMWF WAS MOST EMPHATIC WITH PHASING WHILE PREVIOUS ECMWF RUNS AND RUNS OF THE GFS WERE MORE SEPARATE. EVEN SO...00Z GFS WOULD HAVE WIDESPREAD SNOW ACROSS UPR LAKES ON WEDNESDAY DUE TO INCREASING UPR JET DIVERGENCE/MID-LEVEL FRONTOGENESIS AHEAD OF THE DEEPENING NORTHERN STREAM TROUGH. 12Z GFS TRENDED WEAKER WITH THIS LEAD WAVE OF SNOW FOR WEDNESDAY THOUGH. 12Z ECMWF HAS ALSO TRENDED MORE SEPARATE WITH BOTH STREAMS. SO PROBABLY WILL BE AT LEAST SOME LIGHT SNOW AROUND ON WEDNESDAY WITH STRONG COLD FRONT COMING THROUGH LATER WEDNESDAY INTO THURSDAY LEADING TO BLO NORMAL TEMPS AND LAKE EFFECT SNOWS FOR THE LATER PORTION OF NEXT WEEK FOR MAINLY NORTHWEST WIND SNOW BELTS. && .AVIATION /FOR THE 18Z TAF ISSUANCE/... LOW CLOUDS/LOW MVFR CIGS AT KIWD MAY PERSIST THRU MUCH OF THE AFTN GIVEN NW FLOW OVER THE LAKE ENHANCING CONVERGENCE TOWARD KIWD. HOWEVER...WITH SLIGHT BACKING/WEAKENING OF WINDS INDICATED THIS AFTN...WILL OPT TO SCATTER OUT THE LOW CLOUDS AND RETURN CONDITIONS TO VFR. VFR CONDITIONS WILL THEN CONTINUE THRU THE END OF THE FCST PERIOD. PERSISTENT W TO NW UPSLOPE FLOW SHOULD RESULT IN MVFR CIGS LINGERING AT KCMX THRU TONIGHT. AS WINDS BECOME SSE THU MORNING...EXPECT LOW CLOUDS TO EXIT WITH RETURN TO VFR CONDITIONS. AT KSAW...THERE MAY BE OCNL PERIODS OF MVFR CIGS THIS AFTN...BUT OVERALL DOWNSLOPE COMPONENT TO THE WIND SHOULD WORK TO KEEP LOWER CLOUDS MOSTLY SCT. VFR CONDITIONS SHOULD PREVAIL TONIGHT/THU MORNING AS DEVELOPING OVERRUNNING PCPN NE OF ADVANCING WARM FRONT SHOULD BE NE OF THE AREA THU. && .MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/... WINDS WILL DIMINISH TO UNDER 20KT FROM W TO E TONIGHT INTO THU MORNING AS SMALL AREA OF SFC HIGH PRES SETTLES SE TO JUST N OF LAKE SUPERIOR BY MORNING. LIGHTER WINDS WILL BE SHORT-LIVED AS SOUTHERLY WINDS WILL QUICKLY RAMP UP TO 20-30KT IN THE AFTN DUE TO HEALTHY PRES FALLS SHIFTING E INTO NRN ONTARIO AHEAD OF THE NEXT LOW PRES AREA MOVING E ACROSS SCNTRL CANADA. MAGNITUDE OF PRES FALLS SUGGESTS A SHORT PERIOD OF GALES MAY OCCUR THU EVENING. SINCE MODERATING AIRMASS/INCREASING STABILITY WILL WORK TO LIMIT STRONGER WINDS... HAVE OPTED TO HOLD OFF FROM ISSUING A GALE WATCH AT THIS POINT. 20-30KT WINDS WILL LINGER INTO FRI AS THE LOW PRES AREA TRACKS E JUST TO THE N OF LAKE SUPERIOR. LIGHTER WINDS WILL RETURN FOR SAT/SUN AS THE PRES GRADIENT SLACKENS WITH THE APPROACH OF HIGH PRES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SYNOPSIS...ROLFSON SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
351 PM EST WED JAN 4 2012 .SYNOPSIS... HIGH PRESSURE WILL GRADUALLY BUILD IN ACROSS OUR AREA AND REMAIN IN PLACE THROUGH FRIDAY. EXPECT A WARMING TREND WITH FAIR WEATHER DURING THAT TIME PERIOD. A COLD FRONT WILL BRING INCREASING CLOUDS AND COOLER TEMPERATURES OVER THE WEEKEND. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... WITH HIGH PRESSURE BUILDING OVER THE REGION...CLOUD COVER IS NOW PUSHING EAST OF OUR AREA. SUNSHINE OVER THE PAST COUPLE OF HOURS HAS BEEN MELTING OFF WHAT IS LEFT OF SNOW COVER ACROSS THE WEST. RESIDUAL PATCHES SNOW COVER WILL REMAIN ACROSS THE EAST...WHERE CLEARING OCCURRED LATER IN THE DAY. SKIES WILL REMAIN MOSTLY CLEAR TO START OFF TONIGHT. THIS WILL ALLOW THE BOUNDARY LAYER TO DECOUPLE RESULTING IN LIGHT WINDS. DEWPOINTS ARE STILL IN THE UPPER TEENS ACROSS THE FORECAST AREA. THIS COMBINATION WILL RESULT IN DECENT RADIATIONAL COOLING...WITH TEMPERATURES FALLING RAPIDLY THIS EVENING AFTER SUNSET. A WEAK DISTURBANCE SWEEPING ACROSS LAKE ERIE IS FORECAST TO INCREASE LOW LEVEL CLOUD COVER ACROSS THE NORTHEASTERN HALF OF OUR FORECAST AREA AFTER MIDNIGHT. THIS WILL LEVEL OFF TEMPERATURES ACROSS THOSE ZONES. HOWEVER...DUE TO RADIATIONAL COOLING THE FIRST HALF OF THE NIGHT AND WITH LIGHT SNOW COVER...TEMPERATURES WOULD HAVE ALREADY DROPPED THE LOW 20S. ACROSS THE SOUTHEASTERN HALF OF OUR FORECAST AREA...MOSTLY CLEAR SKIES FOR THE DURATION OF NIGHT WILL RESULT IN TEMPERATURES DROPPING INTO THE LOW TO MID 20S BY SUNRISE. WENT NEAR MOS GUIDANCE FOR LOWS TONIGHT ACROSS THE WESTERN HALF OF THE FORECAST AREA...BUT SLIGHTLY BELOW GUIDANCE IN THE EAST. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS OUR AREA THROUGHOUT THE PERIOD. AS LOW LEVEL RIDGING SLIDES TO OUR EAST THURSDAY...WARM ADVECTION WITH SOUTHWESTERLY FLOW WILL BRING A WARMING TREND TO OUR AREA. BY THURSDAY NIGHT AND THROUGH FRIDAY NIGHT...TEMPERATURES ARE EXPECTED TO BE WELL ABOVE NORMAL FOR THIS TIME OF YEAR. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... LOW PRESSURE OVER EASTERN CANADA WILL DRAG A WEAK COLD FRONT THROUGH THE AREA ON SATURDAY. LATEST MODEL RUNS CONTINUE TO SHOW LIMITED MOISTURE WITH THIS FRONT SO ONLY WENT WITH SLIGHT/CHANCE POPS ACROSS THE FAR SOUTHEAST PORTION OF FA. TEMPS WILL BE WARM ENOUGH SO THAT ANY PRECIPITATION THAT MAY FALL WILL BE IN THE FORM OF RAIN. HIGH PRESSURE BUILDING IN BEHIND THIS SYSTEM WILL THEN PROVIDE AN EXTENDED PERIOD OF DRY CONDITIONS THAT IS EXPECTED TO LAST THROUGH EARLY NEXT WEEK. EARLIER ECMWF RUNS WERE BRUSHING THE NORTHERN PORTION OF CWA WITH SOME PRECIP ASSOCIATED WITH AN UPPER DISTURBANCE MOVING THROUGH THE GREAT LAKES EARLY MONDAY. HOWEVER...THESE RUNS WERE TRENDING FURTHER NORTH AND SHOWING SOMEWHAT WEAKER FORCING. THE 12Z ECMWF NO LONGER HAS PRECIP ACROSS OUR CWA FOR MONDAY MORNING SO DECIDED TO GO WITHOUT POPS FOR THIS PERIOD. THE 12Z GFS AND ECMWF HAVE COME INTO SOMEWHAT BETTER AGREEMENT ON DEVELOPMENT OF 500MB SHORTWAVE TROUGH OVER WRN US THIS WEEKEND. THIS SYSTEM WILL PROPAGATE EASTWARD THROUGH SRN PLAINS DURING THE FIRST PART OF NEXT WEEK AND THEN BECOME ABSORBED INTO LARGER SCALE TROUGH AS IT LIFTS NORTH ON WEDNESDAY. DUE TO INCONSISTENCIES BETWEEN PREVIOUS RUNS...DECIDED ONLY TO INTRODUCE SLIGHT POPS AT THIS TIME FOR THE END OF THE FORECAST PERIOD. TEMPERATURES THROUGH THE EXTENDED PERIOD WILL BE ABOVE SEASONAL NORMALS WITH HIGHS IN THE UPPER 30S AND 40S...AND LOWS RANGING FROM THE UPPER 20S TO LOWER 30S. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... WITH THE RUC AND SREF INDICATING HIGHER CONFIDENCE WITH LL MOISTURE WORKING INTO NORTHERN AREAS AS THE UPR DISTURBANCE RETREATS AND NW FLOW TAKES OVER...HAVE BROUGHT IN A TEMPO PERIOD BETWEEN 08-11Z AT KDAY/KCMH/KLCK WITH THIS POSSIBILITY WITH MENTION OF POTENTIAL MVFR CIGS. OTHERWISE...VFR CONDITIONS TO PREVAIL THROUGH PERIOD. OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...LATTO NEAR TERM...LATTO SHORT TERM...LATTO LONG TERM...KURZ AVIATION...JDR
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1255 PM EST WED JAN 4 2012 .SYNOPSIS... A WEAK UPPER LEVEL DISTURBANCE PASSING THROUGH THE AREA WILL INCREASE CLOUDS THROUGH THE DAY...WITH CLOUDS DIMINISHING ACROSS THE SOUTH AND WEST TONIGHT AND HIGH PRESSURE BUILDS INTO THE REGION. DRY CONDITIONS WILL REMAIN ACROSS THE REGION THROUGH THE REMAINDER OF THE WORK WEEK. && .NEAR TERM /UNTIL 6 AM THURSDAY/... DESPITE RETURNS ON KILN AS HIGH AS 30 DBZ WITH PASSING DISTURBANCE...VIEW OF TDWR DATA CONFIRMS THIS IS ALL MID/HIGH BASED WITH VIRGA AT BEST. LOW LEVELS STILL TOO DRY TO PRODUCE PRECIP WITH THIS PASSING SYSTEM. AS THE MID/HIGH CLOUDS PIVOT OUT OF AREA THIS EVENING...LOW LEVEL MOISTURE INCREASES OVER THE NORTHERN FORECAST AREA OVERNIGHT. THE RESULT WILL BE POSSIBLE LOW CLOUDS THIS AREA...WITH PC SKIES THROUGH THE SOUTHERN HALF OF FCST AREA. && .SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/... HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS THE FA THROUGH THE SHORT TERM TIME FRAME. THERE WILL BE A WARMING TREND THROUGH THE PERIOD WITH TEMPERATURES ABOVE NORMAL FOR THIS TIME OF THE YEAR. TEMPERATURES WILL REACH UP INTO THE UPPER 40S TO MIDDLE 50S ACROSS THE AREA BY FRIDAY. WITH WARM SW FLOW WENT ON THE WARM SIDE OF GUIDANCE FOR TEMPERATURES. && .LONG TERM /SUNDAY THROUGH TUESDAY/... PRECIPITATION WORKS UP INTO THE AREA FROM THE SOUTH ON SATURDAY. THE ECMWF IS FURTHER NORTH WITH THE PRECIPITATION THAN THE GFS HOWEVER THE LATEST ECMWF HAS COME A LITTLE CLOSER IN LINE WITH THE GFS. WENT CLOSE TO THE ECMWF SOLUTION FOR THE LONG TERM PERIOD. PRECIPITATION WILL MAINLY BE IN THE FORM OF RAIN ON SATURDAY HOWEVER AS COLDER AIR WORKS INTO THE AREA SATURDAY NIGHT THERE WILL BE THE POTENTIAL FOR A FEW SNOW SHOWERS TO OCCUR AS WELL. PRECIPITATION WILL MOVE OUT OF THE FA BY SUNDAY. TEMPERATURES WILL STRUGGLE TO RISE ON SUNDAY WITH HIGHS EXPECTED TO BE IN THE MIDDLE 30S TO THE LOW 40S. ON MONDAY A WEAK UPPER LEVEL DISTURBANCE WILL WORK THROUGH THE FA. MODELS ARE IN GENERAL AGREEMENT WITH BRINGING THIS FEATURE INTO THE AREA. MOISTURE IS LIMITED WITH THIS SYSTEM HOWEVER SOME LIGHT PRECIPITATION WILL BE POSSIBLE MAINLY MONDAY MORNING ACROSS THE FA. HIGH PRESSURE WILL RETURN MONDAY NIGHT INTO TUESDAY ALLOWING FOR DRY CONDITIONS ACROSS THE AREA. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... WITH THE RUC AND SREF INDICATING HIGHER CONFIDENCE WITH LL MOISTURE WORKING INTO NORTHERN AREAS AS THE UPR DISTURBANCE RETREATS AND NW FLOW TAKES OVER...HAVE BROUGHT IN A TEMPO PERIOD BETWEEN 08-11Z AT KDAY/KCMH/KLCK WITH THIS POSSIBILITY WITH MENTION OF POTENTIAL MVFR CIGS. OTHERWISE...VFR CONDITIONS TO PREVAIL THROUGH PERIOD. OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...JDR/NOVAK NEAR TERM...JDR SHORT TERM...NOVAK LONG TERM...NOVAK AVIATION...JDR
AREA FORECAST DISCUSSION
NWS NORMAN OK
1151 AM CST WED JAN 4 2012 .AVIATION...VFR SKIES WITH ONLY A FEW CIRRUS THROUGH THE PERIOD. WINDS INITIALLY ABOVE 12 KT AT MOST SITES...BUT WILL DECREASE BELOW 12 KT BY 04/20-23 Z AS HIGH PRESSURE SETTLES IN. WIND DIRECTION WILL GO FROM NORTH TO WEST BY EVENING...AND THEN SOUTHWESTERLY BY MORNING. TAFS FOLLOW THE RUC AND NAM CLOSELY. && .PREV DISCUSSION... /ISSUED 1105 AM CST WED JAN 4 2012/ UPDATE... HIGH CLOUDS WILL CONTINUE TO MOVE OUT OF THE AREA THIS AFTERNOON. BREEZY NORTH WINDS TODAY BEHIND THE FRONT. HOWEVER... WIND SPEEDS WILL GRADUALLY DECREASE THIS AFTERNOON. WILL SEND UPDATES SHORTLY. MAXWELL && PREV DISCUSSION... /ISSUED 417 AM CST WED JAN 4 2012/ DISCUSSION... FOR THURSDAY, SFC WINDS SHIFT SOUTHWESTERLY, BRINGING IN WARMER AND SLIGHTLY DRIER AIR. THE CHANGE IN AIR MASS WILL ELEVATE FIRE DANGER, ALTHOUGH EXPECTED WIND SPEEDS SO FAR SHOULD KEEP IT JUST BELOW RED FLAG CRITERIA. AN UPPER TROUGH WILL BE DIGGING ACROSS THE SOUTHERN PLAINS DURING THE END OF THIS WEEK, BRINGING IN A MODERATE BUT DRY COLD FRONT PASSAGE FOR FRIDAY. THE 1000-850 MB THICKNESS PROGS KEEP THE COLDEST AIR WELL UP IN THE NORTHERN PLAINS, WHILE COOLER AIR SPREADING INTO OUR AREA WILL KEEP TEMPERATURES NEAR SEASONABLE FOR THE WEEKEND. FOR NEXT WEEK, ANOTHER UPPER LEVEL SYSTEM WILL BE DIGGING ACROSS THE SOUTHERN PLAINS. THE LATEST MEDIUM RANGE MODELS DIFFER WITH THE EVOLUTION OF THE SYSTEM. THE GFS PRODUCES A WEAKER SYSTEM, KEEPING THE UPPER LOW AND QPF WELL TO OUR SOUTH ACROSS SOUTHERN TEXAS. HOWEVER, THE ECMWF PRODUCES A MUCH STRONGER SYSTEM, WITH THE UPPER LOW TRACKING ALONG THE RED RIVER, WITH RAIN POSSIBLE LATE TUES TO EARLY WEDNESDAY. FOR NOW, WILL CONTINUE WITH THE GFS DRIER SOLUTION DUE TO MODEL UNCERTAINTIES THIS FAR OUT IN TIME. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 59 33 65 35 / 0 0 0 0 HOBART OK 59 31 63 34 / 0 0 0 0 WICHITA FALLS TX 62 32 69 35 / 0 0 0 0 GAGE OK 58 28 69 29 / 0 0 0 0 PONCA CITY OK 56 33 62 34 / 0 0 0 0 DURANT OK 58 34 61 38 / 0 0 0 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 25/22/22