Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/12/17

Area Forecast Discussion
National Weather Service Caribou ME
1026 PM EST Sat Feb 11 2017 .SYNOPSIS... A weak area of low pressure will track through the Gulf of Maine this evening then move east overnight. Intense low pressure will cross the waters later Sunday night through Monday, then exit across the maritimes Tuesday. && .NEAR TERM /THROUGH SUNDAY/... 1000 PM Update: We cont`d to lower fcst lows a couple of more deg F across the N based on trends seen from mid eve sfc obs. Otherwise...little chg in PoP and cld cvr trends from last fcst... which we gradually show to end across SE ptns of the region late tngt. Left patchy fzfg in the forecast, but more likely, it will be smoke from wood stoves trapped under the sfc base invsn across vly areas spcly across the N that will reduce vsby lcly. Orgnl Disc: The latest radar imagery showed snow winding down w/the heaviest snowfall axis back along the mid-coast say from Penobscot Bay s and w. Sfc analysis showed low pres off of Cape Cod and lifting ene. The inverted trof extends sitting along the coast and showing signs of pivoting back to w. Received reports of 3-4 inches along the Hancock County coast w/1-3 inches in portions of coastal Washington County. Southern Penobscot County received around an inch or so. Further n and w, less snow expected w/< 1". The Downeast coast will see 2-4 inches additional snow into the evening and then activity will wind down as the low pulls away. The satl imagery showed some clearing approaching the Crown of Maine as high pres anchored to the ne re-establishes itself overnight. This clearing is shown by the short guidance to drop into the northern 1/2 of the CWA overnight while the region of the region stays under mostly cloudy conditions. This clearing will lead to some cold temps across the north and west overnight. The NAM12 and RAP matching up quite well the current setup and show temps overnight for the north and west to drop below 0F. Some of the low lying sites across the Central Highlands could dip near or below 0F by early Sunday morning. The downeast areas will see single numbers to lower teens. Also added some freezing fog by early Sunday morning due to waa aloft to set up ahead of the next major event. After a cold start to Sunday morning w/some freezing fog in spots, temps will rebound into the upper teens and lower 20s across the north and west while mid to upper 20s looks good for central and downeast areas. There will be some sunshine across the northern 1/2 of Maine through early afternoon and then increasing clouds expected as low pres apchs from the Great Lakes. Expecting snow to break out across the southern portion of the region by late afternoon and then progress north by evening. Things really get going Sunday night onward. More on this in the Short term section below. && .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/... Low pressure will rapidly intensify while tracking from southern New England into the Gulf of Maine Sunday night through early Monday. The low will then begin to slowly move east later Monday. Snow will expand across the region early Sunday night, with increasing intensities overnight. With the rapid intensification of the surface low and closing of the upper low expect banded snow to develop later Sunday night and persist into Monday across Downeast and central portions of the forecast area. Thundersnow is also possible with strong upward vertical motion later Sunday night into Monday. Snowfall rates of 2 to 4 inches per hour are possible within the heavier snow bands or with any thundersnow. Heavy snow will persist across Downeast and central portions of the forecast area Monday. Winds will rapidly increase Sunday night with strong winds persisting Monday. Wind gusts up to 60 mph are possible along the Downeast coast later Sunday night into Monday, with gusts up to 50 mph Bangor and interior Downeast with gusts of 30 to 40 mph across the remainder of the forecast area. The combination of strong winds and heavy snow will produce blizzard conditions across the Bangor and Downeast region Sunday night into Monday night. The worst conditions are expected later Sunday night into Monday. Have issued Blizzard Warnings for Bangor and the Downeast region from Sunday night through Monday night. Winter Storm Warnings have been issued for much of the rest of the region, with the exception of extreme northern areas. A Winter Weather Advisory has been issued for extreme northern areas where lesser snow totals are expected. Storm total snow accumulations are expected to range from 18 to 24 inches Bangor and Downeast, with 12 to 18 inches across much of the rest of the forecast area. However, lesser accumulations of 6 to 10 inches are expected across extreme northern areas. The snow will taper to snow showers Monday night with the low exiting to the east. However, gusty winds will keep blowing and drifting snow across the region through much of Monday night. High pressure builds toward the region Tuesday. Temperatures will be at near normal, to slightly below normal, levels Monday/Tuesday. && .LONG TERM /TUESDAY THROUGH SATURDAY/... The extended models are in good agreement at the start of the period, then differ mainly due to timing differences. A high pressure ridge will be built into the region between two low pressure systems. One in the North Atlantic heading for the Canadian Maritimes, the other over Eastern Lake Huron. Early Wednesday morning the low over Lake Huron will move east to Lake Erie, as the associated front moves into the North Atlantic the GFS shows a secondary low is forecasted to form over Long Island. The EC forms the low farther south along the coast of VA/NC Wednesday afternoon. the GFS moves the low from Long Island to the southeastern Gulf of Maine. The associated parent low will track into Northern New York. The EC moves its low north to NJ Wednesday evening. Early Thursday morning the GFS transfers the energy from the parent low to the low tracking east along the Downeast Coast. The EC moves the coastal low north to Cape Cod. Thursday morning the GFS moves the low east to central Nova Scotia. The EC moves its low to the sw tip of Nova Scotia. Higher pressure slowly builds into the area as the upper level low slowing moves to the east. The upper level low will finally move east of the area Friday afternoon. Higher pressure will dominate the weather through Saturday morning. A trough will move through the area bringing a chance for snow showers on Saturday. Loaded a blend to smooth out the differences in the models. Used NAWAVE4 for seas in the coastal waters. Used windgust by factor tool. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... NEAR TERM: MVFR/IFR conditions this evening w/some light snow. The heaviest snow and most persistent conditions will be KBGR and KBHB. Conditions are expected to improve across northern areas overnight to VFR for a period and then drop back to MVFR by early Sunday morning w/some freezing fog possible. Expecting MVFR/IFR across KBGR and KBHB through Sunday. SHORT TERM: IFR to VLIFR conditions are expected across the region Sunday night through early Monday night, with improving conditions later Monday night. Strong winds will also develop later Sunday night and persist into Monday night. Wind gusts up to 60 mph are expected along the Downeast coast, with gusts up to 50 mph Bangor and interior Downeast with 30 to 40 mph gusts across the remainder of the region. A Blizzard Warning is in effect for Bangor and the Downeast region Sunday night through Monday night. VFR conditions are expected Tuesday through much of Wednesday, with MVFR conditions possible later Wednesday. MVFR/IFR conditions are possible Wednesday night into Thursday dependent on the eventual track of low pressure. && .MARINE... NEAR TERM: Winds not responding as quickly as early anticipated W/15 KT sustained attm. Decided to back off on winds a bit starting out and then gradually bring them up this evening as low pres pulls way w/15-20 sustained and gusts 25-30 kt. Seas attm were running around 3 ft which is not as high as any of the wave guidance. Dropped back seas by a foot starting out and then brought sea heights up this evening to 4-6 ft. Winds and seas expected to gradually increase during the day on sunday as the pres gradient tightens. SHORT TERM: Winds will increase to storm force levels on the waters Sunday night. A Storm Warning has been issued for the waters from later Sunday night through late Monday night. Gale conditions are then expected later Monday night through Tuesday. Visibilities will be reduced in snow Sunday night into Monday night. && .TIDES/COASTAL FLOODING... Splash over is likely in the normally vulnerable locations along the coast around the time of high tide, which is around midday Monday. The astronomical tides are moderately high, and a storm surge of 1-1.5 ft is expected. A coastal flood advisory may be required around the time of high tide Monday && .CAR WATCHES/WARNINGS/ADVISORIES... ME...Winter Weather Advisory from 7 PM Sunday to 5 AM EST Tuesday for MEZ001>003. Winter Storm Warning from 7 PM Sunday to 5 AM EST Tuesday for MEZ004>006-010-011-031-032. Blizzard Warning from 7 PM Sunday to 5 AM EST Tuesday for MEZ015>017-029-030. MARINE...Storm Warning from 1 AM Monday to 1 AM EST Tuesday for ANZ050>052. && $$ Near Term...VJN Short Term...Norcross Long Term...Norton Aviation...VJN/Norcross Marine...VJN/Norcross Tides/Coastal Flooding...
Area Forecast Discussion
National Weather Service Charleston SC
955 PM EST Sat Feb 11 2017 .SYNOPSIS... High pressure will prevail through Sunday. A cold front will cross the area late Sunday night, with a reinforcing cold front moving through Wednesday night. High pressure will build in late next week. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... 11-3.9 micron imagery shows stratus beginning to develop north of Apalachee Bay. Stratus will continue to expand north through the night. Lowered overnight lows slightly for some areas based on 12/02z observations, but the over flavor of the forecast was maintained. The region will remain along the western flanks of Atlantic high pressure overnight. The strongest warm air advection and low- level moisture return will remain displaced well to the west, thus dry conditions will persist through daybreak. Will have to watch for fog/stratus advecting in from the southwest well after midnight with the highest probabilities for fog remaining across interior Southeast Georgia, possibly oozing as north as Walterboro. Although SREF probabilities for visibilities of 1 nm or less are fairly high across interior southeast Georgia (high as 50-60%), neither the RAP or H3R are showing much in the way of fog development. Suspect given the fairly strong flow atop the boundary layer, much of this will be low stratus versus fog. Opted to maintain patchy fog qualifiers for interior areas from roughly 09-14z. The remainder of the forecast looks on track. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... Surface high pressure will be suppressed to the south on Sunday as a cold front approaches from the northwest. Despite some increase in cloud cover, deep west/southwest flow will boost temperatures to the mid-upper 70s in most locations, well above mid-February normals. The front is expected to cross the forecast area late Sunday night into early Monday. Substantial moisture is lacking, so a dry forecast will be maintained. Weak high pressure will return on Monday and then prevail through Tuesday. Should be a quiet and pleasant couple of days with few clouds. Temperatures will be cooler than Sunday, but still run a tad above normal. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... An upper shortwave crossing the Deep South on Wed will push a cold front through the area Wed night. Somewhat better moisture return ahead of the shortwave should result in at least scattered showers across the area, tapering off Wed night. Dry and cooler Thu-Fri before temps warm back up by next weekend. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... Probabilities are increasing for MVFR cigs to impact both KCHS and KSAV early Sunday, roughly 10-15z. There is even a window for high-end IFR cigs to impact KSAV as fog/stratus develops across interior interior and south of the Altamaha River. Carried a TEMPO group 10-13z for IFR cigs at KSAV to trend. Expect VFR to return by late morning and continue through 13/00z. Extended Aviation Outlook: There are no concerns with a >30% probability of occurrence. && .MARINE... Tonight: A continuation of warm air advection in the low levels over the marine waters will result in a sw flow regime which will tend to mix inefficiently over cooler shelf waters below 60F. Southwest flow will be less than 15 KT with seas 2-3 ft with slightly stronger flow further offshore and beyond 20 NM, closer to the Gulf Stream. Sunday through Thursday: Southwest winds will increase Sunday ahead of an approaching cold front. Winds could approach small craft advisory criteria in the far outer portions of AMZ350 in the afternoon, but it should be fairly short-lived so will continue to assess. The front will cross the waters late Sunday night/early Monday with another brief surge in its wake. Headlines may be needed. Conditions will improve quickly Monday. Weak high pressure will then prevail through mid week with another front to cross Wednesday night. No marine issues expected. && .CLIMATE... Record highs for 12 February: KCHS: 79 set in 1999. KCXM: 76 set in 1898. KSAV: 83 set in 1965. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$
Area Forecast Discussion
National Weather Service State College PA
1043 PM EST Sat Feb 11 2017 .SYNOPSIS... Low pressure will track across the lower Great Lakes on Sunday, before reforming off the New Jersey coast Sunday afternoon. Much colder air will move back into the region on a strong northwest wind Sunday night and Monday. High pressure will return on Tuesday. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... The radar continues to show a band of very light returns from the Midwest into western Pa. So far the nearest surface station reporting precip reaching the ground is Meadville Pa where it is raining lightly. The HRRR suggests some rain finally beginning to reach the ground over my western zones by around midnight, with the chances increasing from there. The overnight over my far northern zones could get slippery in a few spots as lows drop back and flirt with freezing just as some light rain overspreads the area. Right now it looks like the highest chance for a small coating of ice would be over my far northern counties, especially the higher elevations of Potter and Sullivan counties. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... Sunday will be mild and rainy, but turning colder late in the day. As the low undergoes a period of rapid deepening along the coast, a strong NW wind will usher in colder air and allow a favorable Lake Effect fetch to develop for my NWRN counties. The strong NW flow means that there will be the potential for bands of snow showers to even work well inland to the ridge- valley areas. Will keep the winter storm watch for Warren County for now. It may need to be adjusted with the possibility of advisories being needed as well. Will take some time to get the cold air in, and with a complex situation with two lows, the old dry slot routine between the two lows, is something to watch, as QPF could be on the low side between the systems. Still mainly a third period event for our area. New GFS quite wet, did adjust the QPF some, but hard to see a lot of heavy rain on Sunday. Talked to MARFC. Some rises expected. Expect strong gusty winds late Sunday into Monday, possibly warranting wind headlines. && .LONG TERM /MONDAY THROUGH SATURDAY/... Upper level trough will swing through Monday. The trough will deepen and form a low along the NE coast. All models showing it stalling briefly bringing cold northerly flow on the back side of the low. The gradient remains convergent through Monday but the winds will gradually slacken Monday night into Tuesday as a ridge of high pressure slides east from the Ohio Valley. An area of low-mid level warm advection-induced light snow may brush the NW mtns Tuesday as another (initially weak) nrn stream wave approaches from the Upper Glakes. The ensembles vary on timing and placement of low. this could affect the amount of cold air advection and any precipitation. So far have limited any snowfall to higher elevation. SFC low has shifted further north with cold air back into the region mid week through the end of the week. Light precipitation possible with another shot of cold air and gusty NW winds through the mtns. That system will continue to move up the coast and deepen to some degree. Warmer air advecting into the region is possible into next weekend. && .AVIATION /04Z SUNDAY THROUGH THURSDAY/... Widespread VFR conditions across central Pa at 00Z. However, a low pressure system moving east from the Mississippi Valley will spread rain and lowering CIGs across the region late tonight and early Sunday. Based on an examination of latest HRRR and NAM soundings, believe LAMP guidance is a bit too fast bringing in the sub-VFR CIGs. Current thinking is that although rain will arrive in most places between 03Z-07Z, it will take a couple hours to moisten a slice of dry air below 2kft. Therefore, believe the most likely scenario is for MVFR conditions to overspread the area from west to east between 05Z- 11Z and IFR conditions to follow between 08Z-14Z. As low pressure passes east of Pa, expect rain to end with a rapid return to VFR conditions east (downwind) of the Mtns. However, residual low level moisture ascending the Alleghenies will likely produce snow showers and tempo IFR conditions at BFD/JST Sunday evening. Outlook... Mon...Windy. AM IFR shsn BFD/JST. Tue...Sct shsn/VIS reductions possible BFD Tue night. Wed-Thu...Sct shsn/VIS reduction possible BFD/JST. && .EQUIPMENT... KFIG surface observation will be off line until further notice due to failed power feed. && .CTP WATCHES/WARNINGS/ADVISORIES... Winter Storm Watch from Sunday afternoon through Monday afternoon for PAZ004. && $$ SYNOPSIS...La Corte NEAR TERM...La Corte SHORT TERM...La Corte LONG TERM...Lambert/Ceru AVIATION...Fitzgerald EQUIPMENT...
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
839 PM EST Sat Feb 11 2017 .UPDATE... As of 830 PM, a narrow ribbon of light rain extended roughly along the I-96 corridor from Lansing to Detroit. This has been focused along the mid level front, specifically in the 800-700mb layer. Radar trends have shown a slow northward tendency on this band as the mid level frontal circulation slowly lifts toward the north. The regional radar mosaic is suggesting a broadening of the ascent, as indicated by the 18Z NAM and recent HRRR. This suggests the areal coverage of the rain will increase during the course of the evening. There are also indications in the regional mosaic that the lower portions of the frontal circulation across cntrl IL/nrn IN are becoming more active. This aligns somewhat with the latest HRRR which suggests this lower tropospheric forcing will advance across metro Detroit/Ann Arbor and points south overnight as the sfc wave tracks into wrn Ohio. Meanwhile, expecting the mid level sections of the front to remain active enough as it lifts into the Saginaw Valley and thumb late tonight to support a period of mixed precip. There is still however some question as to how well the forcing will hold together across Midland/Bay/Huron Counties. Overall precip type in the going forecast looks reasonable. Sfc web bulb cooling affects along/north of the M 59 corridor may still support a brief interval of freezing rain. While the tri cities and thumb regions will mainly see snow. The latest NAM, RAP and HRRR all suggest the strongest ascent will be exiting east of the area around or shortly after 12Z. In light upstream radar trends, pops will be increased during the overnight. Recent guidance is also suggesting the time period for snow accumulations across the Saginaw Valley and thumb regions will primarily occur in the 09Z to 14Z time frame, with amounts expected to hold at an inch or less. An updated forecast will be issued shortly to reflect these minor precip trends. && .PREV DISCUSSION... Issued at 609 PM EST Sat Feb 11 2017 AVIATION... There have been some reports of light rain out of the radar returns blanketing portions of srn Lower Mi. So far this has been fairly sporadic given the low level dry air. This dry air has also proven efficient in holding ceilings above 8k ft thus far. Mid level frontal forcing will increase during the evening, making rain more probable from FNT south. The strengthening of the forcing and off and on rain will slowly saturate the low levels, supporting a decreasing trend in cloud bases during the night. This may lead to some IFR and/or low end MVFR cigs toward daybreak. Boundary layer temps will support all rain through much of the night, with cooling of the column suggesting some snow mixing at FNT and PTK toward daybreak. Forcing will arrive much later at MBS. This and a cooler thermal profile will support all snow well past midnight. For DTW...Light rain/sprinkles is now occurring in and around metro. The forcing will not be entirely persistent through the whole night. So rain will generally be off and on through the night. Boundary layer temps will remain warm enough to support all rain through the morning. A strong cold front is forecast to arrive between 20 and 22Z Sun afternoon, marked by a wind shift to the west and increase in wind speeds. Gusts may actually top 30 knots. //DTW THRESHOLD PROBABILITIES... * High in ceilings below 5kft after midnight through Sun afternoon. * High in precipitation type tonight and Sun morning being all rain. * High wind cross wind thresholds being exceeded due to strong wind gusts from 270 to 290 deg late Sun afternoon and evening. PREV DISCUSSION... Issued at 307 PM EST Sat Feb 11 2017 DISCUSSION... Broad zone of confluent flow in the middle/upper troposphere currently staging forcing for a modest frontogenetic response in the resultant deformation across the southern Lakes region. However, the lack of moisture quality below 10kft is subverting any precipitation at the surface, contrary to the generous radar depiction. In spite of negligible advective forcing, temperatures have also managed to crawl into the 40s at most locations and dewpoints have a complimentary rise, as well. Rather disheveled weather picture unfolding through the next 24-36 hours across Southeast Michigan. The aforementioned mid-level forcing will continue to make inroads at saturating the column from above, while increasing moisture advection from the southwest occurs overnight. Expecting a band of light precipitation to emerge across south-central portions of the forecast area late this evening and continue through midnight. Precipitation type will be highly dependent upon rates - with liquid being the most likely outcome early. The arrival of the deeper moisture will support an increase in precip coverage overnight. Overall, the NWP suite has been struggling converging onto a preferred outcome, even at this late stage. As the better shortwave forcing approaches from the west toward daybreak, the baroclinic zone should continue to contract - cooling the column enough along and north of I-69 to support a transition to snow. In locations where it is mainly snow at the onset (across the thumb and parts of the Saginaw Valley), accumulations of an inch or two are possible. Overall, prefer an outcome more similar to the RAP/HRRR where surface temperatures remain at or above freezing where precipitation is occuring tonight. As an aside, the NAM family of solutions is far too cold, due to the preservation of a non- existent snow field. Elevated surfaces may still experience a brief period of glazing as the precip converts to snow. Farther south, expecting an all liquid scenario through midday Sunday; after which the column cools enough to transition any left over precip into snow. As the main shortwave barges through the region toward sunset Sunday, respectable cold advective forcing will support a window of higher winds - gusts in the 35-40 mph range. The cold front and the destabilizing boundary layer immediately in its wake will support a multiple hour window of fresh convective snow showers. While individual shower duration will be short, intensity may become an issue. Low pressure associated with an upper wave dropping southeast into Ontario on Tuesday will introduce the chance of rain/snow showers starting in the Saginaw Valley and Thumb regions Tuesday afternoon. As the low moves over the Eastern Great Lakes on Wednesday, northwesterly flow will usher in much colder air with 850-mb temps dropping below -10C across Michigan. A chance for snow showers will continue across Southeast Michigan throughout Wednesday as high temperatures struggle to rise above freezing. High pressure then builds into the region on Thursday bringing drier conditions while cold air remains in place with highs again struggling to get above freezing. Ridging builds over the Great Lakes to end the week as a southwesterly flow brings a gradul warming trend into next weekend. MARINE... Another in a series of low pressure systems will cross south of the Great Lakes late tonight into Sunday, and then phase with a northern stream low passing near Lake Superior and Georgian Bay. This phasing will occur in the vicinity of Lake Ontario Sunday evening with rapid deepening of this system expected as it moves over New England. As this occurs, expect a rapid increase in the gradient flow over Lake Huron by sunset on Sunday with a quick shot of cold air over the upper Lakes. This will lead to a period of northwesterly gales on Sunday night before the deepening low translates to the coast and surface ridging builds into the region for Monday. A Gale Warning has been issued in anticipation of these conditions which should persist from Sunday evening on through much of the overnight hours. While the highest gusts, around 40 knots, will be limited to the open waters of Lake Huron, gusts will approach 35 knots over the near shore waters as well. Yet another low is expected to drop southward through northern Ontario Monday night and Tuesday resulting in a briefly backing wind field over the lakes. This will be followed by another cold frontal passage across Lakes Superior and Huron on Tuesday afternoon and evening, potentially producing another brief shot of gales or near gale conditions. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. Lake Huron...Gale Warning from 6 PM Sunday to 7 AM EST Monday FOR LHZ361>363-421- 441>443-462>464. Lake St Clair...NONE. Michigan waters of Lake Erie...NONE. && $$ UPDATE.......SC AVIATION.....SC DISCUSSION...Mann/JD MARINE.......DG You can obtain your latest National Weather Service forecasts online at
National Weather Service Kansas City/Pleasant Hill MO
504 PM CST Sat Feb 11 2017 .Discussion... Issued at 235 PM CST SAT FEB 11 2017 Fairly tight temperature gradient present across the region this afternoon as a warm front settles across the I-70 corridor. This warm front will likely not make it much further north as the surface low associated with this front is currently located just southwest of the KC Metro, and moving east/northeast with time. Expect areas in the E/NE winds north of I-70 to remain in the 60s this afternoon, but areas south of that warm front have climbed well into the 70s. NOTE: Not looking at a record for Kansas City, since KCI is along or just north of front, and under some pesky stratus, which is mitigating the 70+ degree temperatures at the airport. Otherwise other parts of KC would likely make a run at the 73 degree record for Feb 11. Through the rest of the afternoon, as the surface low moves through the area the winds will come around from the northwest, which will bring in cooler temperatures for the rest of the weekend. Expecting temperatures to dwell in the upper 40s to lower 50s on Sunday (depending on how the stratus behaves). Model soundings indicate some very thin stratus through the morning and early afternoon hours on Sunday, but give how dry the midlevels of the atmosphere will be, as well as decent mixing through the morning, there is a chance that the stratus could wear off by the early afternoon. and while cold air advection will persist through the day, diabatic heating could bring temperatures up into the 50s for Sunday, again with some cooperation from the lingering morning clouds. Fire weather concerns will be elevated on Sunday as dry surface conditions will combine with gusty northwest winds to create quickly spreading fire conditions. More information about the fire weather concerns can be found in the fire weather discussion below. Above normal temperatures will persist throughout next week, with virtually no chance for precipitation for our region. The best and likely only chance for precpitiaion will come early to middle part of the upcoming week as a closed mid level trough lumbers through the Southern Plains. With the best lift likely staying well south of the area the only real chance for any precipitation will be south of HWY 50, and even that region doesn`t look favorable for any notable precipitation. A bit of a warm up back into the 60s is possible for the late part of the week. Model solutions certainly look favorable for an anomalously warm day come Friday. Mid level ridging aloft will provide good subsidence and an expansive surface trough will push a warm front well north of the area. Assuming this pattern holds true through the late part of the week, there is a chance that temperatures will need to be bumped up a few more degrees as we approach that day. && .Aviation...(For the 00Z TAFS through 00Z Sunday Evening) Issued at 503 PM CST SAT FEB 11 2017 Forecast trends away from prevailing MVFR cigs with mainly VFR conditions expected. Currently, limited MVFR cigs exist, downstream at that, with only scattered VFR stratus hovering north of the surface front. Going closer to how SREF ensembles and RAP handle moisture content in the boundary layer over the next 12 hours. && .Fire Weather... Issued at 235 PM CST SAT FEB 11 2017 Gusty northwest winds will push through the area Sunday, likely starting up Saturday evening, and increasing in speed through the overnight hours. By early Sunday morning N/NW winds will be around 15 to 20 mph, with gusts around 20 to 30 mph. Current RH forecast is expected to be in the 25 to 35 percent range, mainly across western Missouri and eastern Kansas. The further east you go the higher the RH is expected to get. Should the morning stratus linger through the afternoon it would likely prevent some mixing, which could keep the winds on the lower end of the aforementioned window. However should the clouds wear off earlier in the day, then more mixing could occur and NW winds could be in the 20 to 30 mph range, with RH values dropping to near 30 percent. A Red Flag Warning for Sunday is not anticipated at this time. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ Discussion...Leighton Aviation...Blair Fire Weather...Leighton
Area Forecast Discussion...UPDATED
National Weather Service Fort Worth TX
910 PM CST Sat Feb 11 2017 .UPDATE... After an exceptionally warm day (DFW tied and Waco set their respective daily max temperatures today...see products RERDFW and RERACT for further information), a cold front will send us back towards normalcy on Sunday. Regional surface analysis reveals our aformentioned cold front is just entering northern Oklahoma as winds have begun to snap around out of the north. While the front is moving at around 15 mph, it will quickly be gaining forward speed this evening with the cessation of mixing and the addition of stout pressure rises to the north. As a result, have sped the timing of the front up a bit from the previous forecast, and now show FROPA across our far northwestern counties around 4 am, and into the Metroplex as early as 6 am, and then through Waco around 9 am. In addition, upstream surface observations reveal that dewpoints are already in the middle 30s across northwestern portions of Kansas. Comparison of short-term trends to model output reveal that both the GFS and NAM are having a difficult time resolving the dry air behind the front, and this is subsequently negatively impacting both statistical and blended guidance (which is too moist). As a result, trended dewpoints downwards towards the RAP which has been handling trends much better in the post-frontal airmass. In addition, wind speeds were increased a bit for Sunday morning and into the afternoon. Stout cold advection (at least initially) will combine with a notable isallobaric component (pressure rises on the order of +2 to +2.5 mb/hr) to result in strong and gusty north winds behind the front. A wind advisory will likely be required for perhaps the northwestern half of the CWA, but will defer this decision to the midnight crew. Finally, there is some concern that near-critical fire weather thresholds may be met for a brief period across our northwestern counties as cold advection weakens, potentially allowing temperatures behind the front to warm into the upper 60s or even near 70 degrees. This would allow afternoon RH values to fall under 30 percent, although wind speeds should be slowly decreasing through the afternoon, mitigating the duration of impacts. Carlaw && .AVIATION... /ISSUED 555 PM CST Sat Feb 11 2017/ /00Z TAFs/ Concerns...MVFR and possible IFR cigs at Waco tonight. Strong cold front arrives Sunday morning with strong and gusty north winds and more MVFR cigs for all the TAF sites. Waco Airport...Low level stratus is expected to move north this evening, reaching KACT around 08Z. Some guidance suggests Waco may remain on the western fringe of the stratus deck as the lower level winds start to veer ahead of an approaching cold front, and we will be closely monitoring the extent of the stratus as it moves north later this evening. Assuming the stratus does affect Waco, initially cigs are expected to be around 1 kft but may briefly lower into IFR between 8-11Z. As the lower level winds continue to turn to the west ahead of an approaching cold front, the stratus will likely shift east around daybreak resulting in a short window of VFR before MVFR cigs invade behind the cold front. The front will arrive around 15Z, and by midday, wind speeds are expected to have increased to 18G28kt. Cigs between 2-3 kft are expected to prevail through the afternoon hours. DFW Airports...Wind speeds will subside over the next few hours with VFR conditions prevailing. Nearly all guidance has removed the pre-frontal MVFR stratus from the Metroplex and thus have removed it from the TAF, but will be closely watching the trends through the evening hours. Veering winds ahead of the front suggest any stratus will remain east of the DFW airports, but may clip KDAL for a brief period overnight. The front will arrive around 12Z, and wind speeds will increase to 20-25 kts gusting around 30 kts. These strong winds will continue through the day with a slight decrease in speeds by 00Z. MVFR stratus with cigs between 2-3 kft will invade the TAF sites behind the front, but a brief hour or two of cigs betwen 1.5-2 kft is possible with the initial arrival of the post-frontal stratus. Very low end VFR cigs are expected by mid-late afternoon. JLDunn && .PREV DISCUSSION... /ISSUED 343 PM CST Sat Feb 11 2017/ An early-summer like day is in progress across North Texas with temperatures soaring into the upper 80s and lower 90s. The deep westerly flow aloft has allowed unseasonably warm temperatures to build across much of the Southern Plains today. Temperatures have climbed to 97 degrees at Vernon, TX and Altus, OK over the last hour and a mesonet site near Altus was 99 degrees. Needless to is abnormally warm across the region with temps in our area about 30 degrees above normal. The heat will give way by tomorrow though as a strong cold front moves into North Texas. The front is currently located across southern Kansas and will likely enter our northwest CWA by early Sunday morning...entering the Metroplex around 8am or so and clearing the remainder of the CWA by early afternoon. While temperatures won`t be sharply colder...they will fall back into the 60s through the day Sunday. Gusty north winds will also make it feel much colder. Sustained winds of 20 to 30 mph with higher gusts may require a wind advisory for parts of North Texas at least through the morning hours. Ahead of the front tonight...moist southerly flow will continue with another round of low clouds expected to spread across parts of North Texas into early Sunday morning. Areas along and east of I-35 should see most of the cloud cover. There could also be some patchy fog mainly across the southeast during this time. The main story over the next few days will be the increasing precipitation chances late Sunday through Tuesday across most of Texas. A strong shortwave trough currently over California will continue to move east through the remainder of the weekend. With the cold front spreading a shallow cool airmass across much of Texas...this approaching upper low will set the stage for several days of cloudy and cool weather with increasing rain chances. An initial wave of ascent will spread atop the cooler air late Sunday night and will be the first surge of moisture back into the region. Some light rain is possible with this initial wave mainly across the southern counties. During the day on Monday as the upper trough gets closer...much stronger forcing for ascent will overspread West Texas and eventually North Texas. A surface trough will deepen and gradually allow a warm front to spread into our southern counties by late Monday night. This is when our rain chances will increase significantly...especially west of I-35 where the strongest lift will be located. Areas of moderate to sometimes heavy rainfall will spread from west to east across the region late Monday night into Tuesday. The bulk of the heavy rainfall is likely to move east of us by Tuesday evening. Lapse rates are generally weak and there isn`t expected to be any surface based thunderstorm chances don`t look all that great. There is some weak elevated instability so we`ll keep a mention of isolated thunderstorms mainly late Monday night. Precipitation chances will linger into late Tuesday night as the core of the upper low moves over North Texas. By Wednesday...the entire system should be east of the area. There will be a threat for some locally heavy rainfall through Tuesday. At this time...forecast rainfall amounts of 1 to 2 inches over 36 hours shouldn`t be too significant to be concerned about widespread flooding issues. Wednesday through the end of next week looks dry with temperatures gradually warming back into the 70s by the end of the week. Dunn && .PRELIMINARY POINT TEMPS/POPS... Dallas-Ft. Worth 58 66 44 53 44 / 0 5 10 30 80 Waco 59 68 49 55 48 / 0 5 20 30 80 Paris 58 65 40 51 43 / 5 10 10 10 50 Denton 55 64 41 52 42 / 0 5 10 30 90 McKinney 57 65 42 51 43 / 0 5 10 20 70 Dallas 59 67 45 53 45 / 0 5 10 30 80 Terrell 61 67 46 53 46 / 5 10 10 20 50 Corsicana 61 68 47 55 48 / 5 10 20 20 50 Temple 59 68 47 55 50 / 0 10 20 30 80 Mineral Wells 53 64 42 51 41 / 0 5 10 50 100 && .FWD WATCHES/WARNINGS/ADVISORIES... None. && $$ 82/90
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
234 PM PST Sat Feb 11 2017 .SYNOPSIS...Scattered showers and isolated thunderstorms will be possible, mainly in Kern county through the evening hours. Otherwise, dry weather with patchy dense late night and early morning fog will be possible in the San Joaquin Valley through Wednesday. Unsettled weather returns to central California on Thursday. && .DISCUSSION...An upper low is currently moving southeast and just moved into San Luis Obispo county. This low caused scattered showers and thunderstorms to develop, mainly in the desert. MRMS indicates rainfall rates of just over a half an inch an hour north of Randsburg with the public reporting minor roadway flooding in the area. This activity is forecast to continue, spreading west into the evening hours. The HRRR did a good job capturing this activity this morning and indicates showers should dissipate shortly after 02z Sunday. The upper low will continue to move quickly south tonight into Sunday with an upper ridge building over central California Sunday into the first half of the week. This will result in the possibility of areas of dense fog through the San Joaquin Valley each night and early morning from Sunday through at least Wednesday. Please monitor the forecast closely, especially if you plan on traveling in the valley during the morning hours this week. An upper low in and around the Aleutian Islands in Alaska will move very little from Monday through Friday bringing another round of unsettled weather to central California. An upper level shortwave associated with this low will move east toward the Pacific Northwest and northern California coastline Wednesday night into Thursday, with precipitation spreading south into the area as early as Thursday morning. This will be a quick moving system, with precipitation spreading south into Kern county by Thursday afternoon into the overnight hours. Another upper trough looks to approach the California coastline over the weekend, however there are significant timing differences with the forecast models. Regardless, expect a period of unsettled weather again Thursday into the end of the week. && .AVIATION... MVFR to occasional IFR cigs through the terminals until at least 00z. Otherwise, patchy reduced visibilities will be possible early Sunday morning. && .AIR QUALITY ISSUES... None. && .CERTAINTY... The level of certainty for days 1 and 2 is high. The level of certainty for days 3 through 7 is medium. Certainty levels include low...medium...and high. Please visit for additional information an/or to provide feedback. && .HNX Watches/Warnings/Advisories... NONE. && $$ public...Riley avn/fw...Durfee synopsis...Riley
Area Forecast Discussion
National Weather Service Lincoln IL
847 PM CST Sat Feb 11 2017 .UPDATE... Issued at 846 PM CST Sat Feb 11 2017 Low pressure center is just west of St. Louis this evening and tracking rapidly eastward, expected to be just east of Paris, IL by Midnight. In the mean time a band of low level frontogenetical forcing has set up north of the low from just north of Macomb to Pontiac producing scattered to numerous light showers in this slowly moving band. Have raised PoPs in this area as the band looks to be relatively persistent until midnight as the low moves east and drier subsident air moves in with approaching high pressure. Otherwise...lows dropping into the 30s for much of central IL from I-72 northward tonight still look good as cooler temperatures are poised just to the north, despite current temperatures in central IL quite mild at the moment ranging from 46 in Galesburg to 59 at Mt Carmel airport. && .SHORT TERM...(This evening through Sunday) ISSUED AT 254 PM CST Sat Feb 11 2017 20z/2pm surface analysis shows 1005mb low near Kansas City...with stationary frontal boundary extending into north-central Illinois. The low is progged to track E/NE along the boundary and reach KHUF by around 06z/12am. As the low approaches, the boundary layer will moisten sufficiently to create overcast conditions and perhaps a few rain showers. High-res models such as the WRF-ARW and HRRR suggest the showers will become most numerous across the E/NE KILX CWA by mid to late evening. Will therefore focus highest PoPs in the likely category along/northeast of a Bloomington to Robinson line this evening. Any rain that occurs will be quite light...generally amounting to a tenth of an inch or less. Given the moistening conditions and expected light/variable winds near the baroclinic zone, think areas of fog will develop as well. Once the low pushes into Indiana and winds become N/NW after midnight, any lingering showers will end and visibilities will rapidly improve from west to east overnight. High pressure will build into the Plains on Sunday, allowing skies to clear across central Illinois. With a tight pressure gradient in place, brisk northwesterly winds gusting to 25-30mph will bring cooler air into the region. Despite the CAA...afternoon highs will still be above normal for this time of year...with readings mainly topping out in the 40s. Further southeast...temps will reach the lower 50s south of I-70. .LONG TERM...(Sunday night through Saturday) ISSUED AT 254 PM CST Sat Feb 11 2017 Cool high pressure will advance into Illinois Sunday night into Monday, with the center of the high tracking across Illinois just south of I-70 Monday afternoon. That will set the stage for a continuation of the cooling trend started on Sunday. Still lows Sunday night and highs on Monday will remain slightly above normal. Low pressure dropping south from Hudson Bay to the central Great Lakes will drag a cold front into Illinois late Monday night into Tuesday. At the same time, a 500 mb shortwave will advance across southern Illinois in the NW upper flow, possibly triggering a few showers just south of our forecast area. The GFS and NAM, and to some extent the Canadian, all indicate some light rain in or near our southeast counties from Flora to Lawrenceville Monday night. At the very least, clouds will overspread our southern counties, possibly as far north as I-74 Monday night. That system will depart quickly to the east of Illinois on Tuesday, but the cold frontal passage will bring a reinforcing push of colder air, dropping highs and lows to right around normal for Tuesday night through Thursday. Wed night looks to be the coldest night of the next week, as a cold pool in the lower troposphere passes across the northeastern half of Illinois. We expect lows Wed night to range from around 20 north of Peoria, to the mid 20s south of Jacksonville to Lawrenceville. Previous runs of the ECMWF had indicated some Lake effect snow showers could drift as far south as Vermilion county on Wednesday, but this mornings 12z run has backed off of that solution, with just a gradual increase in diurnal clouds Wed afternoon due to steeper low level lapse rates in our NE counties. Beyond Thursday, increasing southerly flow and ridging aloft will help to provide a warming trend into next weekend. Highs Friday should reach the lower 50s, with Saturday`s readings in the mid to upper 50s. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 551 PM CST Sat Feb 11 2017 Low pressure approaching along a frontal boundary across central IL will promote IFR/MVFR cigs and light rain showers this evening...especially south of KPIA-KBMI. As the low center will pass east of the area by 06Z...showers should diminish from 6-10Z followed by VFR conditions developing in gradually clearing skies from 10-18Z. Winds initially ranging from SE-NE up to 8 kts becoming NW overnight. Wind speeds increasing to 15-20 kts with gusts 25-30 kts by 18Z. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...37 SHORT TERM...Barnes LONG TERM...Shimon AVIATION...37
East Central Florida Forecast Discussion
National Weather Service Melbourne FL
945 PM EST Sat Feb 11 2017 .DISCUSSION... Overnight the forecast remains on track for 50s across most areas with near 60 along and east of US Highway one and the beaches. With the light to calm winds over to cooler spots some patchy fog is expected to materialize by early Sunday. HRRR derived vis product shows the best area for development generally north of I-4. The current forecast is in good shape and no adjustment is planned. The ridge axis will be a little farther south on Sunday, which will promote southwest flow over more of the area. This will delay the east coast sea breeze, allowing max temps to reach 80 right along the coast and lower 80s elsewhere. && .AVIATION...VFR except for a chance of shallow fog early Sunday. Have only mentioned MVFR visibility restriction category in the TAFs. && .MARINE... Tonight-Sunday...Surface ridge axis over the waters will produce a southwest/south wind flow. Speeds will mainly be 10 knots or less, except maybe up to 12-13 knots in the north tonight. An east swell is forecast to slowly diminish so boating conditions look good the remainder of the weekend. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$ JP/MB
Area Forecast Discussion
National Weather Service Marquette MI
659 PM EST Sat Feb 11 2017 .SHORT TERM...(This evening through Sunday) Issued at 332 PM EST SAT FEB 11 2017 12Z raobs/latest wv imagery and RAP analysis show a fast zonal flow over the Cndn border to the n of a flat upr rdg over the se half of the CONUS. Sfc hi pres over NW Ontario is extending a rdg axis into the Upr Lks under some large scale subsidence ahead of a shrtwv rdg axis aprchg the area, but lots of lo clds linger in the shallow moist lyr with llvl nne flow under sharp invrn base near h875 shown on the local 12Z raobs. There is some clrg over ern Lk Sup with some dry advection and downsloping winds in the nne flow off Ontario, and this clrg is aprchg the ern cwa. Looking to the w, there is a shrtwv over Alberta moving quickly e into the Plains and supporting a sfc lo pres that is now moving into srn Saskatchewan. Main fcst concerns in the short term portion of the fcst wl be on impact of shrtwv/sfc lo pres now moving e just n of the Cndn border, mainly sn amounts and winds. Tngt...Although there could be some breaks in the lo clds over the ern cwa late this aftn into the evng, mocldy skies with dry wx wl be the rule thru midngt. But then as the shrtwv to the w slides esewd and toward nrn MN by 12Z Sun, some fairly vigorous dpva/deep lyr qvector cnvgc and upr dvgc in the left exit of supporting 150kt h3 jet max wl overspread the area after 06Z, bringing some sn to perhaps all but the far e by 12Z Sun. Absence of sgnft mstr inflow and poor sn/water ratios under 15:1 with fairly hi/narrow dgz wl limit sn totals, but presence of 2-2.5g/kg specific humidity at h7 would support up to 2 inches of sn by sunrise over portions of the w where the dynamic forcing/pcpn wl arrive earliest. Since the 12Z NAM shows an elevated warm lyr impacting the far scentral closer to some very warm air aloft associated with the upr rdg over the se CONUS, included a mention of some freezing ra for a time, mainly over the s half of Menominee County. Expect relatively ltl diurnal temp fall, with the lower readings more likely over the e/ncentral where some llvl dry air wl persist longer into this evng. Sun...As the shrtwv/area of deep lyr forcing shift to the e, the hier categorical pops wl push into the ern cwa early in the day, but diminish w-e as the disturbance continues to move steadily to the e. Since the shrtwv is progged to amplify a bit, with 12hr h5 hgt falls fm 06Z-18Z Sun in the 150-180m range, suspect the e half may see up to 3-4 inches before the pcpn diminishes later in the day. Another sgnft impact wl be some very gusty nw winds as h925 winds are fcst by the 12Z NAM/GFS to incrs to 40-45kts behind the accompanying cold fropa, strongest over the ern cwa. Although the caa in the wake of the shrtwv is not fcst to be too intense, drawing h85 temps as lo as only about -14C into the Upr Lks, fcst sdngs show enuf llvl destabilization that resulting mixing may cause some wind gusts at least aprchg advy criteria, especially at exposed locations near Lk Sup e of Marquette. These strong winds wl cause some blsn even though the sn may be rather wet. The arrival of this trailing thermal trof may cause some les after the larger scale forcing exits to the e, but marginal h85 temps/rather quick trend toward a more neutral/acyc flow ahead of aprchg sfc rdg axis and under vigorous large scale subsidence wl limit the intensity of this pcpn. Since the wet sn totals and winds be highest over the ern cwa, opted to issue a winter wx advy now for Alger/nrn Schoolcraft/Luce Counties, where the winds will be strongest and most likely to reach advy criteria/cause more extensive blowing sn. .LONG TERM...(Sunday night through Saturday) Issued at 332 PM EST SAT FEB 11 2017 Ongoing lake enhanced snow and strong NW winds over eastern Lake Superior and eastern Upper MI associated with a shortwave will diminish pretty quickly Sun night. A Winter Weather Advisory has been issued until midnight Sun night. See the short term discussion for more details. There is still uncertainty pertaining to strength, timing and track of a shortwave mid-week. Best consensus at this time brings lake enhanced snow Tue the trailing LES Tue night that gradually diminishes into Thu. Big story beyond that is building warmth across the region. 850mb temps look to be above 0C from late Fri through at least early next week. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 659 PM EST SAT FEB 11 2017 MVFR cigs should linger at KIWD/KCMX/KSAW thru this evening as low-level moisture remains trapped under inversion. Then as a strong disturbance approaches from the w late tonight, the arrival of steady snow will cause conditions to drop into the IFR range for at least several hrs at all terminals. Conditions may fall to LIFR at KCMX for a few hrs. Following the passage of the disturbance and associated cold front, a wshft to strong/gusty wnw winds will create BLSN, especially at the more exposed KCMX terminal where winds will gust to around 35kt. The BLSN at KCMX may lower vis to LIFR during the morning/early aftn. KIWD/KSAW will improve to MVFR in the morning as -shsn diminish/end and with expectation of BLSN not being as significant. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 332 PM EST SAT FEB 11 2017 Opted to upgrade going gale watch to a warning for the entire lake this forecast as the pres gradient is forecast to sharpen significantly over the Upper Lakes on Sunday following the passage of a vigorous upper disturbance. The arrival of colder air over the relatively warm lake waters will enhance destabilization as well and the mixing of the stronger winds to the surface. Expect nw winds gusting as hi as 45 kts over the eastern lake Sunday afternoon and evening. The approach of a trailing hi pres ridge and slowly weakening pres gradient will cause diminishing winds w-e on Sun night. Winds diminish below gale force by Monday morning. Winds will then strengthen to gusts near 30 kts Mon night into Tue night. Freezing spray is expected Mon night central and eastern Lake Superior. Another round of freezing spray, and some heavy freezing spray, is expected late Tue into early Wed over mainly the central and east. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... Winter Weather Advisory from 4 AM to 10 PM EST Sunday for MIZ006- 007-085. Lake Superior... Gale Warning from noon Sunday to 4 AM EST Monday for LSZ266-267. Gale Warning from 7 AM EST /6 AM CST/ to 7 PM EST /6 PM CST/ Sunday for LSZ162-263. Gale Warning from 10 AM to 10 PM EST Sunday for LSZ264-265. Lake Michigan... Gale Warning from 10 AM to 10 PM EST Sunday for LMZ248-250. && $$ SHORT TERM...KC LONG TERM...Titus AVIATION...Rolfson MARINE...KC/Titus
Area Forecast Discussion
National Weather Service New York NY
943 PM EST Sat Feb 11 2017 .SYNOPSIS... Low pressure tracks from the Ohio Valley to the Central Appalachians tonight, to the south of Long Island Sunday, then to the east of Cape Cod as it rapidly deepens Sunday night. High pressure over the mid section of the country follows on the heels of intense low pressure departing to the east of New England on Monday. The high passes off the Mid Atlantic coast on Tuesday. Low pressure then tracks north of the area Wednesday, sending a cold front across the region. High pressure then returns for the end of the week. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... Minor adjustments made based on latest observations. Colder air is still dropping southward across the Connecticut Valley with reading already into the upper 20s and lower 30s in northern CT. The HRRR and RAP show some colder air working across CT and LI overnight, colder than currently forecast. This will have to be watched. Northern stream shortwave ridging crosses the area tonight, keeping things dry for most of the night. However, isentropic ascent sets up on SW-WSW low level flow late tonight, and the column should moisten sufficiently to bring precipitation as far east as around the NY/CT border and Nassau/Suffolk County border by 6 am. Precipitation will initially be light, and based on progged warm layer around 800 hPa should begin as some light sleet or freezing rain. Lows tonight were based on a blend of NAM 2-meter temperatures and MET/MAV/ECS guidance, and should be around 5 degrees above normal. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... Good agreement on a developing stacked low aloft tracking into the eastern Great Lakes Sunday, then down across New England to off of Cape Cod by Monday morning, that tracks to the south of Long Island Sunday evening and then to near Cape Cod by Monday morning. Though track is similar, faster GFS timing is not favored. The models have come into general agreement on a slightly colder solution than previously. Noting historical problems with the GFS maintaining shallow low level cold air, have discarded the GFS low level thermal profiles. Given similarity and recent good performance, have used a blend of NAM and CMC- Reg profiles for determining p-type with surface temperatures a blend of NAM 2-meter temperatures with MET and ECS guidance, then adjusted towards the wetbulb temperature when precipitating. The result, is now expect wintry precipitation throughout the CWA. Looking at NAM and CMC-Reg soundings, freezing rain is now expected across most if not all of NYC/Long Island/NE NJ from around 11-15z, along with a light accumulation of snow and sleet. The colder air will be slower to erode to the N/NE so expect more snow elsewhere and still some freezing rain. Over the lower Hudson Valley, there is some residual low level warm air from the inland low that should move in during the afternoon and produce some sleet as well, helping to limit snow accumulations there. Across interior portions of S CT, expect mainly snow, with some freezing rain possible Sunday afternoon. Expect precipitation to change back to all snow Sunday night as cold air moves in behind the storm. With the low forecast to rapidly expand as it deepens, the precipitation end time is somewhat uncertain, but it appears that precipitation should linger over at least eastern areas for most if not all Sunday night. Based on this the following updates have been made to winter weather advisories: NYC/Long Island/most of NE NJ/S Westchester/Fairfield: 2AM-NOON Sunday - up to 1 inch of snow/sleet and up to a few hundredths of ice. Depending on exactly how fast cold air builds in behind the storm/how long precipitation lingers Sunday night - higher snow totals maybe needed especially over eastern Long Island. Most of the Lower Hudson Valley + parts of NE NJ: Midnight tonight to Midnight Sunday night - 2-4 inches of snow and sleet and up to a tenth of an inch of ice. Interior S CT: 4 AM Sunday-6 AM Monday - 3-6 inches of snow, with a little bit of sleet mixed in, with up to a few hundredths of an inch of ice. Note - depending on how long snow lasts Sunday night and exact set up of deformation axis behind the storm, higher snow totals warranting a warning cannot be ruled out. S Central and SE coastal CT: 4 AM-5 PM Sunday - 1-3 inches of snow/sleet and up to a few hundredths of an inch of ice. Depending on exactly how fast cold air builds in behind the storm/how long precipitation lingers Sunday night - higher snow totals maybe needed. && .LONG TERM /MONDAY THROUGH SATURDAY/... A closed upper low passes off the New England coast on Monday followed briefly by shortwave ridging on Tuesday. At the surface, intensifying low pressure along the New England coast deepens to 970 mb as it passes to the south of Nova Scotia Monday evening. With high pressure building east from the mid section of the country, this will result in very strong NW winds Monday with gusts up to 50 mph for most locations, strongest near the coast. Right now, this is looking to be on the level of strong wind advisory with criteria falling just short of a high wind warning. In addition, there is a low chance of light snow Monday, mainly across eastern LI and SE CT as the low departs. Not expecting any accumulating snow at this time. Highs will remain in the 30s on Monday. Went below MOS guidance and leaned toward colder model 2m temperatures. High pressure then briefly follows for Tuesday. The next feature of interest will the another amplifying shortwave trough dropping SE across the Great Lakes on Tuesday, again closing off as it heads into the Northeast Tuesday night into Wednesday. At the same time, a southern branch closed low gets sheared out out between the two streams across the southeast, with secondary low development well offshore on Wednesday. The ECMWF 24 hours ago had the two streams phase with a strong coastal low impacting the area for the mid week. Since then, much of the global models keep the two streams unphased, with the low far enough offshore to spare the region significant precipitation. That being the case, this will need to be closely watched in subsequent model runs. The GFS is more progressive than the ECMWF and GGEM, and develops the secondary even farther north along the New England coast, far too late to have a significant impact other than gusty NW winds on the backside. A consensus forecast results in a low chance of snow Wednesday and that will be the approach for this forecast cycle, with the best chance being to the east of NYC. High pressure follows for the end of the week with temperatures generally at or just below normal. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... Low pressure approaches from the west late tonight...tracking se of LI Sunday aft/eve...then rapidly intensifying s/e of New England Sun Night into Monday. Light and variable winds bcmg NE overnight. E/NE winds of 10 to 15 kt expected Sunday...highest along the coast. Occasional gusts to 20 kt possible for coastal terminals Sunday morning. VFR conditions through 09z, with conditions lowering to mvfr/ifr late tonight into Sunday morning in wintry mix. FZRA/PL likely for city terminals Sun morning...with mix of SN/PL/FZRA for northern and eastern terminals. By 18z...A coating/glaze of sleet/ice possible for city terminals...with 1 to 3 inches of snow/sleet and glaze of ice for KBDR/KHPN/KGON...and 2 to 4 inches for KSWF. Potential for a brief period of snowfall rates of 1/2 to 1" per hour for northern terminals Sun morn/aft. .OUTLOOK FOR 00z SUNDAY THROUGH THURSDAY... .Sunday Night...IFR/LIFR into early evening. RA for city/LI terminals...with wintry mix likely at inland terminals. Additional light snow/sleet accumulation and glaze of ice likely for KSWF/KBDR/KGON/KHPN. A gradually improvement in conds late Sunday Night...with transition back to scattered snow showers from w to e. Spotty additional light accum possible with this...particularly across northern terminals. .Monday...Snow showers threat ending. Otherwise VFR. NW wind 25-30 KT with gusts 35-45 KT. .Tuesday...VFR. NW gusts to 20 kt. .Wednesday...Potential for MVFR or lower in rain/snow. .Thursday...VFR. Gusty NW flow. && .MARINE... Marginal sca ocean swells expected to remain just below 5 ft. Otherwise...a relatively relaxed pressure gradient over the region will keep conditions below SCA levels on all waters tonight. Strengthening easterly flow ahead of approaching low pressure should have 25-30 kt winds developing Sunday morning into afternoon over the ocean with seas building to SCA as well. SCA gusts also possible for a brief period of time Sun aft funneling down LI sound. Will hold off on SCA there due to brief duration at this time. Winds should briefly subsiding Sun eve as low pressure works over ocean waters. In it wake...NW winds rapidly ramp up after midnight Sun night as low pressure intensifies SE of Cape Cod...reaching storm force on the ocean and gales nearshore towards daybreak Mon. Winds will increase on Sunday as a clipper system passes to the north and a cold front moves across the waters. Winds and seas may reach SCA levels Sun into Sun night with a brief period of gales possible on the ocean. For the next system, there is a bit of uncertainty with how quickly winds ramp up Tue night into Wed as a warm front pushes north of the waters. Gales are possible Wed night into Thu, but it could be sooner. There is the increasing likelihood of storm force gusts on the ocean and gales on the remaining waters late Sunday night into Monday as low pressure rapidly deepens off the New England Coast. Winds diminish Monday night, coming below 25 kt everywhere by early Tuesday morning. 25 kt winds possible once again on Wednesday night into Thursday. && .HYDROLOGY... Around 1/2 to 3/4 of an inch of liquid equivalent is forecast to fall from late tonight through Sunday night. At this time, no hydrologic impact is expected, as at least some of this will fall as freezing/frozen precipitation. There is some potential for significant precipitation during the middle of the week. && .TIDES/COASTAL FLOODING... Low pressure tracks south of the area on Sunday and then rapidly deepens off New England coast Sunday night into Monday. 1 1/2 to 2 ft surge needed to reach minor coastal flood thresholds during Sunday morn/eve high tides. The easterly flow is only about 12 hours on Sunday before shifting around to a NW gale Sunday night. For the Sun morning high tide cycle water levels should stay below minor flood thresholds...except perhaps briefly touching for the most vulnerable Western Great South Bay locales. Water levels may touch or slightly exceed minor thresholds for the southern and eastern bays for the Sun night high tide cycle due to tidal piling...with the remainder of the region likely staying below minor thresholds as winds will be weakening/shifting NW. Will hold off on any statement at this time due to wind forcing uncertainty and marginal nature of event. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...Winter Weather Advisory from 2 AM to noon EST Sunday for CTZ009. Winter Weather Advisory from 4 AM Sunday to 6 AM EST Monday for CTZ005>008. Winter Weather Advisory from 4 AM to 5 PM EST Sunday for CTZ010>012. NY...Winter Weather Advisory from 2 AM to noon EST Sunday for NYZ071>075-078>081-176>179. Winter Weather Advisory until midnight EST Sunday night for NYZ067>070. NJ...Winter Weather Advisory from 2 AM to noon EST Sunday for NJZ004-006-104>108. Winter Weather Advisory until midnight EST Sunday night for NJZ002-103. MARINE...Gale Watch from late Sunday night through Monday afternoon for ANZ330-335-338-340-345. Storm Watch from late Sunday night through Monday afternoon for ANZ350-353-355. Small Craft Advisory from 10 AM Sunday to 1 AM EST Monday for ANZ350-353-355. && $$ SYNOPSIS...Maloit/DW NEAR TERM...JC/Maloit/DW SHORT TERM...Maloit LONG TERM...DW AVIATION...JC MARINE...NV/DW HYDROLOGY...Maloit/DW TIDES/COASTAL FLOODING...
Area Forecast Discussion
National Weather Service Norman OK
606 PM CST Sat Feb 11 2017 .UPDATE... Adjusted temperature trends through the overnight. && .DISCUSSION... Quick evening update, temperatures are still in the upper 70s to mid 80s across the region, with upper 80s across western north Texas. Previous forecast was more bullish with cooling through the evening. Adjusted temperatures accordingly, but the challenge is how fast temperatures cool with calm winds and mostly clear skies through midnight, before the arrival of the surface cold front from the north. The latest RAP has an okay handle on the expected trend, fitting current conditions and how the forecast is expected to evolve overnight. In response, did increasing overnight lows one or two degrees, primarily across northern Oklahoma and locations where temperatures were well into the mid to upper 90s for several hours this afternoon. Kurtz && .PREV DISCUSSION... /issued 515 PM CST Sat Feb 11 2017/ DISCUSSION... AVIATION... /For the 00z TAFs/ VFR conditions are expected through the end of the TAF period. Gusty southwest winds at the very beginning of the TAF period will subside quickly and may become variable for a period before a cold front moves through later tonight. Northerly winds will strengthen behind the cold front and continue through tomorrow afternoon. PREV DISCUSSION... /issued 237 PM CST Sat Feb 11 2017/ DISCUSSION... After an unbelievably warm day across the area today, a cold front will push south through the area tonight, bringing in more seasonal weather. Main concerns for tonight will be associated with the wind shift and strong gusts and any ongoing fires. Expect to see gusts over 40 mph and will issue a wind advisory for portions of western/southwestern Oklahoma and western north Texas late tonight and through much of the day Sunday. Sunday will feel quite a bit colder, even with temps expected to top out in the 50s most places, with the strong winds continuing throughout much of the day before relaxing late. By Sunday night into Monday slow moving storm system will begin to impact the area with increasing precip chances. There still appears a chance for some sleet/snow to mix in with the rain across far western parts of the area early on Monday, before changing back to all rain during the day. Could also see a rain/snow mix across far northern Oklahoma Monday night, but again it would be light and do expect any accumulations to occur. Otherwise, much of the area will see some much needed rain, with the best chance across the southern half of Oklahoma south into north Texas late Monday and Monday night. Ecmwf cont to be a bit more aggressive with precip chances across the area lingering at least through the day on Tuesday before shifting to the east. This should give us at least a temporary reprieve from the fire weather concerns. From the middle of the week into next weekend things look dry with a warming trend. Models differ as we get to the end of the forecast with regards to precip chances with the ECMWF remaining dry, while GFS brings another shot of rain to parts of the area. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 45 55 35 47 / 0 0 10 50 Hobart OK 45 55 33 43 / 0 0 10 70 Wichita Falls TX 50 59 38 47 / 0 0 10 60 Gage OK 40 50 31 41 / 0 0 20 70 Ponca City OK 44 52 34 49 / 0 0 10 30 Durant OK 54 62 43 51 / 10 10 10 20 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...Red Flag Warning until 7 PM CST this evening for OKZ004>030- 033>040-044-045. Wind Advisory from 3 AM to 3 PM CST Sunday for OKZ014-016- 021>025-027>029-033>041-044>046-050. TX...Red Flag Warning until 7 PM CST this evening for TXZ083>090. Wind Advisory from 3 AM to 3 PM CST Sunday for TXZ083>090. && $$ 04/12
Area Forecast Discussion
National Weather Service Pittsburgh PA
838 PM EST Sat Feb 11 2017 .SYNOPSIS... Low pressure will bring rain and warm temperatures overnight into Sunday. Snow showers and colder air will return for the start of the new week. && .NEAR TERM /THROUGH SUNDAY/... Mesoanalysis shows a 700mb front across the northern periphery of the forecast area. Moisture remains meager down through 850mb, but is increasing per latest RAP guidance. Have thus introduced chance pops along this boundary, increasing to likelies near midnight. This light rain will eventually lift north of the area. Elsewhere, continued to slow the arrival of precipitation with the system tonight. Finally, rain showers are developing across northern KY and southern IN, about 3-5hrs after previous model guidance had suggested. Pushed back POPs about 3 hours, along with the accompanying overcast conditions. Will keep categorical POPs through early Sunday as the surface low passes directly overhead. Rainfall totals will be fairly underwhelming, averaging less than half an inch. Still, with the recent snowmelt and up to half an inch of rain, streams and creeks will rise. Widespread precipitation will move east of the area Sunday afternoon as the Mid-Atlantic low takes over. A brief lull in precipitation should be realized, before northwest flow develops. An impressive pressure gradient will begin to tighten Sunday afternoon, and with cold air advection occurring, intensifying winds aloft should have little trouble mixing down to the surface. Gusts in the Ridges will approach Advisory criteria by Sunday evening. TAx && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... Updated Sunday night through Monday morning for the inclusion of High Wind Watch in the mountains of WV and MD. Guidance continues to show deep mixing behind the cold front, tapping into a stout 60+ knot jet near the descending tropopause. Previous Discussion... Wind gusts will really crank up Sunday evening, especially in the ridges. The higher elevations appear likely to reach advisory criteria and probably Warning criteria. In addition to the winds, snow showers will pick up as well. There is some uncertainty as to exactly when rain will change over to snow, and considering the dynamics involve, the changeover could have an impact on how much snow occurs, considering the evening should be the period of heaviest precipitation. The typical locations in the ridges and I-80 corridor will have the highest snowfall totals, and the need for winter weather advisories can`t be ruled out in these areas. Both wind gusts and snow should be settling down by Monday morning, with accumulating snow expected to be over by Monday afternoon. High pressure will enter the region on Monday and bring a brief tranquil period. Highs will drop 5 to 10 degrees below normal on Monday and rise back slightly above normal on Tuesday. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... As northwest flow develops through the middle part of the week, cooler air will bring a chance of snow showers as temperatures drop below normal once again. By Thursday night precipitation chances should come to an end. Temperatures should moderate for Friday and Saturday. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... Some scattered shra are developing as mid level moisture streams across the FKL to DUJ corridor this evening. This will continue with a very slow lowering of the ceilings up there for several more hours. It should remain as this activity crosses. However, farther south, MVFR cigs are not very far south of the area as Gulf moisture streams northward. Rain will eventually develop as stratus envelops the area overnight. Have slowed the timing of rainfall, however all sites will likely go IFR for a decent period as moisture surges through overnight. A strong jet off the deck from the WSW will mean some LLWS chances toward morning and in the morning hours S and W of PIT. This will end as a cold front crosses the area in the afternoon and gusty W winds ensue. Beyond the valid TAF period, wind gusts will likely increase further. Fries .OUTLOOK... Restrictions can be expected into early Tuesday as cold flow in the wake of the aforementioned low supports stratocu and snow showers. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...High Wind Watch from Sunday afternoon through Monday afternoon for MDZ001. OH...None. PA...None. WV...High Wind Watch from Sunday afternoon through Monday afternoon for WVZ512>514. && $$