Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/07/17

Area Forecast Discussion
National Weather Service Bismarck ND
920 PM CST Mon Feb 6 2017 .UPDATE... Issued at 910 PM CST Mon Feb 6 2017 The 18-00 UTC global models and the HRRR through its 02 UTC iteration favor a southward shift in the area of heaviest snow overnight into southwest North Dakota across the Beach, Medora, Dickinson and Killdeer areas, possibly extending south towards Amidon and Mott. Two to four inches of snow are possible for these areas by Tuesday morning as a band of moderate to at times heavy snow across Montana as of 03 UTC in association with strong 850-600mb frontogenesis interacting with steep mid level lapse rates propagates east. For now, will not expand the Winter Weather Advisory into southwest North Dakota given the marginal advisory level accumulations that are possible. UPDATE Issued at 537 PM CST Mon Feb 6 2017 The first of two snow bands currently across central North Dakota as of 2330 UTC will continue to propagate into eastern North Dakota. A second band of snow across Montana will approach the North Dakota border around 04-05 UTC, propagating into central North Dakota around 08-10 UTC. Near term PoPs were blended to observed trends through 23 UTC, and the 18-21 UTC high resolution suites thereafter. && .SHORT TERM...(This evening through Tuesday) Issued at 238 PM CST Mon Feb 6 2017 The main forecast concern for the short term will be the accumulating snow across northern North Dakota. Several periods of snow are forecast to track across northwest and north central North Dakota the rest of this afternoon and tonight. The global models are all in good agreement in this scenario. This should result in 4 to 7 inches of snow across northwest North Dakota and 3 to 5 inches north central by noon on Tuesday. Added Mckenzie county to the winter weather advisory as the snow forecast looks to be close to 5 inches there. Otherwise the current advisory looks good. By Tuesday afternoon the snow will be tapering off and the cold Surface high will begin to slide southeast with its very cold air. The temperatures on Tuesday will only warm a few degrees most places with highs only in the single digits. .LONG TERM...(Tuesday night through Monday) Issued at 238 PM CST Mon Feb 6 2017 There are several issues in the extended forecast. First the arctic surface high will move south into the Northern Plains Tuesday night through Thursday morning. Morning lows will be 10 to 20 below both days. Highs on Wednesday will be 5 below to 5 above. Wind chills will be 20 to 40 below both mornings with a little rebound during Wednesday afternoon. Its possible a wind chill advisory will be issued for Tuesday night through Wednesday night on the day shift Tuesday. Following the cold air, a significant warmup will follow beginning in the west Thursday and continuing across the region Friday through Monday. Currently the warmest day will be Friday with highs into the mid 40s southwest and mostly 30s elsewhere. Saturday through Monday will see highs in the upper 20s and 30s. Only small chances for precipitation are in the extended. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) Issued at 910 PM CST Mon Feb 6 2017 A band of moderate to at times heavy snow across eastern Montana as of 03 UTC will spread across western and central North Dakota tonight with IFR/LIFR conditions. Snow will decrease across the area late tonight into Tuesday morning. MVFR ceilings will continue through much of the day on Tuesday. && .BIS WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until noon CST /11 AM MST/ Tuesday for NDZ001>005-009>013-017. && $$ UPDATE...AYD SHORT TERM...WAA LONG TERM...WAA AVIATION...AYD
Area Forecast Discussion
National Weather Service Taunton MA
1007 PM EST Mon Feb 6 2017 .SYNOPSIS... A storm moving through the Great Lakes will bring a wintry mix to the region Tuesday morning changing to rain in most locations Tuesday afternoon. However, an extended period of freezing rain may persist across the interior high terrain into Tuesday evening. Low pressure races out of the Southern Plains and passes south of New England. If this storm comes close enough, it could bring several inches of snow to our region. Whether it will come close enough is still highly uncertain. High pressure builds in with drier colder air from Thursday night through Friday night. Two weather systems then affect us over the weekend, bringing a chance of snow Saturday and rain or snow Sunday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 10 pm update... Mostly clear skies across CT/RI and southeast MA combined with light winds has resulted in temps cooling quicker than guidance has indicated. Thus have lowered temps across the region. Otherwise previous forecast remains on track. Regarding new 00z guidance...00z NAM has trended a tad slower with onset of precip...with very little if any qpf thru 12z...then precip overspreading the region 12z-15z. Latest HRRR and RAP along the same lines as it takes some time for deep layer moisture and lift to arrive. However can/t rule out spotty light precip before 12z. If this verifies the morning commute before 7 am may be mainly dry. Will wait to review remainder of the 00z guidance before making any changes to the forecast. Previous discussion... Clouds will continue to overspread the region this evening as a result of warm advection commencing aloft. The deepest moisture/lift will be north of the region tonight, so overall it should remain dry for most areas overnight. However, we may see a brief period of light snow late this evening into the overnight hours north of the MA Pike with the highest risk near the NH border. Any accums from this potential initial band should be very minor, but a coating of snow is certainly possible. Low temps will mainly be in the 25 to 30 degree range. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... *** Snow develops between 5 and 9 am Tuesday across northern MA with some freezing rain in areas south of the MA Pike and inland from the coast which may impact the morning rush hour *** *** Most locations change to rain Tuesday afternoon but an extended period of freezing rain may persist into Tuesday evening across the higher terrain *** Tuesday... Precipitation Types and Timing... Approaching shortwave will back mid level flow increasing the forcing for ascent. In response, expect precipitation to overspread most of the region from southwest to northeast between 5 and 9 am. As has been the case most of the winter, specific ptypes/amounts will be tricky as a small model error in thermal profiles may result in a significant difference in the outcome. Will break it down more specifically below. North of MA Turnpike... Model soundings indicate that thermal profiles will probably be cold enough for a period of snow north of the MA Turnpike and especially near the NH border Tuesday morning. Our best estimate is between 1 and 3 inches with the highest amounts near the NH border. Forecast confidence in these amounts is low given marginal thermal profiles, so later shifts may certainly need to make adjustments. Ptype north of the Pike and along the coast should turn to rain by afternoon, but a period of freezing rain is expected across the interior. We are concerned that the models might be warming the boundary layer too quickly given northeast flow, especially across the higher terrain where freezing rain may persist into Tuesday evening. There may be a small area across far northwest and north central MA that receives over a quarter inch of ice accretion with even a low risk of amounts approaching one half inch. This may result in the potential for isolated power outages and will mention that in the Winter Weather Advisory. Also, shallow cold air may try to work back into northeast MA for a time Tuesday evening behind the initial weak wave of low pressure. So while temps may rise sharply toward daybreak Wednesday, they may fall back to near freezing for a time Tue evening resulting in a change to a period of freezing rain across portions of northeast MA, something later shifts will have to watch closely. South of MA Turnpike... To the south of the MA Turnpike, model soundings indicate that thermal profiles will be too warm to support snow even Tuesday morning. However, the concern is for a period freezing rain developing between 5 and 9 am inland from the coast with surface temps below freezing. While our confidence is highest in this across northern CT/northwest RI, a period of freezing rain is possible further south into Rhode Island and interior southeast MA. Given that this may impact the Tuesday morning rush hour opted to extend the advisory further south and east into these locations given potential impacts. Ptype should change to rain in most of this area by late morning or early afternoon at the latest. Tuesday night... Mainly looking at periods of rain showers across the region Tue night. However, as mentioned we are concerned about freezing rain persisting across portions of the interior high terrain into Tuesday evening. Will also need to watch northeast MA for shallow cold air trying to temporarily work into the region behind the initial wave of low pressure. Temps should climb above freezing toward daybreak in all locations, especially coastal plain as strong low pressure tracks well to our northwest and we begin to warm sector. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Big Picture... Longwave scale shows zonal flow mid to late week, but with a hint of cyclonic flow centering on or near Hudsons Bay. Over the weekend, the cyclonic flow over the East becomes more notable as longwave high pressure builds over the Pacific Coast, with our flow coming from NW Canada. Shortwave scale shows two troughs moving through during the period. One sharp trough from northern Canada moves through New England Thursday, and a trough out of Alaska arrives early next week. The GFS and ECMWF mass fields are similar through Friday and then diverge over the weekend. The GGEM diverges by Thursday with an outlier solution on the storm that passes to our south at that time. A blend led by GFS/ECMWF is favored for the long term. Details... Wednesday... Weak shortwave moves through, but with little moisture. Expect a few clouds but otherwise dry weather. Mixed layer extends a little above 925 mb, with temps in the layer supporting max sfc temps mid to upper 40s northwest and 50s the remainder of the region. Wednesday night-Thursday.... Southwest flow aloft brings increasing clouds Wednesday night. Low pressure wave moves out of the Southern Plains and across the Mid Atlantic coast. Model timing and placement of the low is a challenge. The 12Z GFS and 00Z ECMWF describe a track that crosses the 40N/70W benchmark, while the GGEM is roughly 300 miles farther south and the 12Z ECMWF is just north of the GGEM. Meanwhile the GFS is fastest of the models in shooting the core of the pcpn over us by 12Z Thursday. With all of these uncertainties, it is hard to pinpoint timing or placement of heaviest amounts. The track places New England on the cold side of the storm, so precip in most areas should be snow. Areas such as Cape Cod and Nantucket could see some mixing with rain. The best chance for the snow would be in RI and SE Mass and especially near the South Coast. Snowfall amounts will be highly dependent on the storm track, with a northern track such as the GFS bringing several inches while a southern track such as the GGEM may leave trace amounts or less. Friday through Monday... High pressure builds for Friday and brings fair weather. A weak shortwave from the Pacific NW may bring a chance of pcpn Friday night/Saturday morning. Trough digging over the Plains generates a more impressive surface low that moves up the St Lawrence Valley Sunday. The trough takes on a negative tilt, which could support a coastal redevelopment late Sunday or Sunday night. The system moves off to the northeast by Monday. This looks like an unsettled period, especially Sunday and Sunday night, with rain or snow changing to rain. This will need to be monitored. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 03z update... Only change or trend is precip may arrive a few hours later than 12z guid indicted...with widespread precip overspreading the area 12z-15z. Any precip before then may just be light and spotty. Will wait and review all 00z guid before making any changes. Short Range /through Tuesday night/... Tonight...Moderate to high confidence. VFR for most of the night. Potential for MVFR cigs starting around 08Z or 09Z. Winds become variable early tonight, but trend to an ENE wind toward morning. Tuesday and Tuesday night...Moderate to high confidence. Low end MVFR-IFR conditions develop in most locations between 11z and 15z as precipitation overspreads the region. Ptype should start as snow north of the Pike which changes to rain along the coast by early afternoon, but a period of freezing rain likely for the interior. Ptype likely begins as freezing rain south of the Pike and inland from the coast before changing to rain in most locations by mid afternoon. LLWS develops Tue night with mainly IFR to localized LIFR conditions persisting in mainly rain showers, except some freezing rain may continue into the evening across the high terrain. KBOS TAF...High confidence in TAF. KBDL TAF...High confidence in TAF. Outlook /Wednesday through Saturday/... Moderate confidence. Wednesday... Conditions improve to VFR in the morning. Southwest winds shift from the West-Northwest during the afternoon. Potential gusts to 25 knots during the day, diminishing in the evening. Wednesday night-Thursday... Ceilings lowering to MVFR after midnight. MVFR with areas of IFR in light snow Thursday especially over RI and SE Mass. Winds increase from the northwest Thursday afternoon with gusts to 25 knots possible. Friday-Saturday... VFR Friday as high pressure moves overhead. Ceilings lowering to MVFR Friday night and Saturday morning with areas of IFR possible in snow showers. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Range /through Tuesday night/... Tonight...High confidence. Weak pressure gradient will keep winds and seas below small craft advisory thresholds. Tuesday...Moderate to high confidence. Initial wave of low pressure will generate a period of northeast wind gusts of 25 to 35 knots Tuesday afternoon and early evening across our northeast outer waters. Hoisted a Gale Warning for our northeast most outer-waters where winds will be the strongest. Tuesday night...Moderate to high confidence. Main low pressure tracking well to our northeast will allow winds to shift to the southwest with gusts between 20 and 30 knots. Seas will build to between 5 and 9 feet across most open waters and headlines will be needed. Outlook /Wednesday through Saturday/... Moderate confidence. Wednesday... Southwest wind turns from the Northwest as a cold front moves through. Winds will gust to 25 knots, especially in the afternoon northwesters, then diminish at night. Seas will start the day at 5 to 9 feet on the outer waters and exposed southern waters, then slowly diminish through the day. Small Craft Advisories will be needed. Thursday... Vsbys lower in snow and mixed rain/snow first thing Thursday morning. Precipitation tapers off by evening. Northwest winds turn from the North and increase again with gusts to 25 knots. Winds then turn from the Northwest overnight but maintain gusts to 25 knots. Seas of 5 to 7 feet linger on the outer waters, with lower heights closer to shore. Small Craft Advisories will be needed. Friday... Northwest winds gust to 25 knots Friday, then diminish as high pressure builds overhead. Seas of 5 to 8 feet linger on the outer waters Friday. Small Craft Advisory will be needed. Saturday... High pressure moves off to the east, and a disturbance races across from the Great Lakes. Winds turn from the South-Southwest but with speeds remaining below 25 knots. Lingering 5 foot seas on the southern outer waters. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...Winter Weather Advisory from 5 AM to 7 PM EST Tuesday for CTZ002>004. MA...Winter Weather Advisory from 5 AM to 11 AM EST Tuesday for MAZ013-017-018. Winter Weather Advisory from 5 AM to 1 PM EST Tuesday for MAZ007-014. Winter Weather Advisory from 5 AM to 7 PM EST Tuesday for MAZ005-006-009-011-012. Winter Weather Advisory from 5 AM Tuesday to 3 AM EST Wednesday for MAZ002>004-008-010-026. RI...Winter Weather Advisory from 5 AM to 11 AM EST Tuesday for RIZ002>004. Winter Weather Advisory from 5 AM to 7 PM EST Tuesday for RIZ001. MARINE...Small Craft Advisory from 7 PM Tuesday to 7 AM EST Wednesday for ANZ235-237. Gale Warning from 1 PM to 10 PM EST Tuesday for ANZ250. Small Craft Advisory from 11 AM Tuesday to 7 AM EST Wednesday for ANZ251-254>256. && $$ SYNOPSIS...WTB/Frank NEAR TERM...WTB/Frank/Nocera SHORT TERM...Frank LONG TERM...WTB AVIATION...WTB/Frank/Nocera MARINE...WTB/Frank
Area Forecast Discussion
National Weather Service State College PA
1026 PM EST Mon Feb 6 2017 .SYNOPSIS... A weather system will arrive tonight bringing widespread rain and showers lasting into mid-week. Mild temperatures Tuesday and the first part of Wednesday will be replaced by colder and blustery conditions for the second half of the week. A wave of low pressure sliding by across the Virginias will likely bring at least a few inches of snow to the southern half of the state Wednesday night into Thursday morning. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... A bkn deck of cirrus clouds across practically all of the region this evening will be replaced by a shield of altocu and altostratus clouds, then eventually NS clouds late. Rain will spread into the area shortly (within 60-90 minutes) after the leading edge of this mid cloud deck reaches any one location. The onset time to the rain will be across the Laurel Highlands and West- Central Mtns around 05Z...across the Central Mtns between 06-07Z...and across the region north and east of KIPT after 07Z. There is a little concern for a brief period of -FZRA for the first hour or two of the precip across the northern mtns around or shortly after midnight...and over the Western Poconos during the predawn hours. However, latest HRRR confirms earlier thinking that a light southeast to southerly wind will kick up just as this ovc cloud deck arrives from the southwest...and will boost temps just above freezing as the rains begins. Thus, the risk for widespread glaze is looking quite minimal. 8H temps are very mild and rising very quickly. SREF probs of FZRA are below 10pct, but NAM and hi-res WRF do generate a spot of ZR around 09z in/near KIPT & Wellsboro. Will maintain just a chc of FZRA in those areas (and will expand the mention of the chc -fzra back to near KBFD and a few surrounding counties. Temps will stay comfortably above Freezing across the Laurel Highlands, South-Central mtns and Lower Susq Valley. mins there will be in the U30s to L40s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/... Tuesday will feature abnormally warm temperatures with 50s and l60s widespread. There will be scattered/numerous showers. The combination of rainfall and snow melt will bring rises in area rivers and streams, but flooding is not expected at this time. The QPF is highest in the NW but still <1 inch. Only a half of an inch or less is expected elsewhere. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... Rain will taper off to light showers Tue night as a strong cold front moves through overnight. Scattered rain showers will mix with and may change over to snow showers by Wed mid-morning in the NW mountains. Drying conditions to the east. AS cold front stalls over mid atlantic states, ECMWF and the GFS develop a wave that rides along it on Wed night into early Thu. ECMWF/GFS both move it off to the northeast quickly but before it departs, it brings the possibility of a couple to several inches of snow across the southern mountains and susq valley. High pressure slide across VA on Friday with weak wave moving in front the northwest Fri night into Sat with light snow poss. Warm air advection will bring clouds in starting Fri night with chances for light snow changing to a mix then rain later Sat into Sun. Temps will be dropping Wed and Thu as colder air works in behind the cold front. Thu into Fri looks to be the coldest period before WAA brings a more moderate airmass back into the region for the weekend. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... Widespread VFR noted across central Pa this evening. However, deteriorating conditions will develop late tonight, as rain overspreads the region in advance of a warm front approaching from the Ohio Valley. Plenty of low level moisture, combined with a southerly flow, should result in the lowest CIGs at BFD, due to orographic lift. Both SREF and HRRR output support this scenario with IFR/LIFR CIGs indicated at BFD for most of Tuesday. Elsewhere, expect CIGS/VSBYS falling into the low MVFR/high IFR range late tonight as rain arrives, then rising CIGs and rain tapering to scattered showers is expected later Tuesday, as surface warm front lifts northward through the region. An increasingly strong southwest flow aloft, combined with light surface winds, will likely result in LLWS overnight and Tuesday across parts of the region. As warm front pushes north across the state, expect the threat of LLWS to abate over southern Pa by afternoon, but could continue over the northern airfields into Tuesday evening. Outlook... Wed...AM low CIGs possible BFD/JST. Snow possible southern Pa Wed night. Thu...Early AM snow possible southeast Pa. PM shsn/squalls possible, mainly BFD/JST. Fri...Evening light snow possible NW Mtns. Sat...Low CIGs possible W Mtns. && .EQUIPMENT... KFIG surface observation will be off line for an extended period of time due to failed power feed. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Dangelo/Lambert NEAR TERM...Lambert SHORT TERM...Lambert/Dangelo LONG TERM...Ross/RXR AVIATION...Fitzgerald EQUIPMENT...Lambert
Area Forecast Discussion
National Weather Service Lincoln IL
910 PM CST Mon Feb 6 2017 .UPDATE... Issued at 910 PM CST Mon Feb 6 2017 Dense fog is expected to linger ahead of an advancing warm frontal boundary. Improvement in the dense fog is expected to advance from south to north as the warm front arrives, and showers/storms develop across C and SE IL. The dense fog advisory will likely be cleared first in southern counties later this evening, with the northern counties continuing through the 1 am ending time. We remain in a slight risk for severe storms tonight east of I-55, with large hail the primary hazard and damaging winds possible. HRRR output indicates we should see more widespread showers/storms develop toward 10 pm, then shift northeast by 2 am as the warm front lifts north of our counties. Spotty showers could linger behind the warm front the rest of the night, mainly along the Illinois river valley per the HRRR. A cold front will push across central IL Tuesday morning, reaching near I-57 by 10am, triggering another round of showers/storms for eastern Illinois from 10 am to Noon. Those counties are in a slight risk for Day 2/Tuesday, with hail and isolated wind damage possible. Those storms should depart into Indiana by early afternoon, with little additional precip expected Tuesday afternoon. Temps tonight will be quite warm for this time of year, with upper 40s and 50s common. Highs tomorrow will approach record high temps for Feb 7. A cold frontal passage will begin a noticeable cool down for mid week. Updates this evening were done to the weather/PoP grids to slow down the onset of widespread precip a couple hours. Dense fog was added to the grids earlier. Updated forecast info is already available. && .SHORT TERM...(This evening through Tuesday) ISSUED AT 258 PM CST Mon Feb 6 2017 Mid afternoon surface analysis shows deepening 995 mb low pressure over east central WY, which has a warm front extending eastward to along the WI/IL border. Low stratus and fog had spread northward across much of CWA by mid afternoon in warm sector, with some peaks of sunshine over Knox and Stark counties. Still have some areas of dense fog lingering over east central IL from Bloomington and Rantoul-Champaign southward to Mattoon. SSE winds of 6-13 mph had milder temps in the mid to upper 40s, with lower 50s along highway 50 in far southern CWA and at Galesburg which enjoyed more sunshine today. Latest forecast models takes 995 mb surface low pressure to nw IL by 12Z/6 am Tue, and then deepens ne to 992 mb over southern Lake MI by 18Z/noon tue and to 987 mb over central Lake Huron by 6 pm Tue. Associated cold front to sweep eastward across IL during Tue morning. So far radar mosaic showing just very isolated/spotty light rain or drizzle southeast of the IL river at mid afternoon. Models agree with developing widespread rain showers northward during late afternoon and evening and then diminishing behind cold front from west to east during Tue morning with slight pops Tue afternoon east of I-57 and northeast of I-74. Models continue to show MUCAPES in the 500-1500 J/kg range tonight and lingering over southeast IL Tue morning. This combined with bulk shear of 40-45 kts supports SPC`s slight risk east of I-55 during late evening and overnight and lingering southeast of Terre Haute to Flora line Tue morning. A 15% risk of large hail from elevated thunderstorms and 5% risk of damaging wind gusts. Temps nearly steady or even rising a bit more tonight with mild lows lows in the mid 40s form I-74 north and upper 40s/lower 50s sw CWA. Highs Tue range from the low to mid 50s over northern CWA, to mid 60s in southeast IL. This will be approaching record highs in the mid to upper 60s in southeast IL. .LONG TERM...(Tuesday night through Monday) ISSUED AT 258 PM CST Mon Feb 6 2017 The weather system effecting the CWA tonight and tomorrow will quickly push to the east tomorrow night, resulting in a very brief period of dry weather before the next weather system moves into the area. This next weather system will be a quick hitting clipper that the models have had trouble coming into agreement with. Models now seem to be in better agreement with all models except the Canadian bring the precip through on Wednesday. The Canadian has a little precip in southeast IL during the day, but the main time period is Wed night. Will keep with the consensus and have the precip during the day. Temps behind the current system will begin falling Tue night and should be cold enough on Wed for all the precip to be in the form of snow...except in the southeast where temps 38 to 42 will be possible by Wed afternoon. So, any precip that does fall in the southeast Wed will become a mix of rain and snow, then change to all rain for the afternoon. Snowfall accumulations should remain north of I-72, with the highest amounts from one half to one inch along and north of I-74 in Mclean, Champaign, and Vermilion counties. Remainder of the week with be dry as high pressure builds into the region. Temps will start on the cool side, but then warm quickly for Fri, and then warmer for Sat. The next weather system will move into the area for the weekend. All the precip should be just rain showers as very warm air will once again advect northward for the weekend. Models looking a little better in agreement than past couple of days; but, except for Sat evening, pops through the period will be in the chance category. Pops for Sat evening will be likely and higher in the northeast parts of the CWA due to an active warm front lifting northward through the area. Models still showing some differences with the timing of this system, so how long precip will linger in the CWA is questionable. Current forecast show precip ending Sun afternoon with dry weather for Sun night and Monday. Temps will be cooling on Wed and then fall to below normal for Thur and Thur night. Then as high pressure shifts east of the CWA, the latter part of the week will be warm, with warmest temps being Sat, when the southeast gets into the lower 60s. Beyond next weekend, temps will cool some, but remain above normal for Feb. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 622 PM CST Mon Feb 6 2017 VLIFR fog will affect the I-74 corridor for at least the first half of the evening, and could linger through 06z before the onset of rain showers helps to mix out the boundary layer and cause the dense fog to thin a bit. Cigs will remain in the 200-400FT range for the northern terminals as well. SPI has seen conditions improve to MVFR with 4sm BR and OVC016, while DEC has remained LIFR with 1/2sm FG and VV002. Improvement in the fog and ceiling heights will advance from south to north as rain and storms develop across the area after 03z. HRRR output shows a focus for storms mainly between 03z and 08z, before the primary band of precip shifts to the northeast. There could be isolated redevelopment after the line departs, but coverage of storms with that wave look very isolated in the HRRR. Wind shear appears likely between 08z and 14z, due to the development of a LLJ at 2K FT around 40kt from 220 deg. After 14z, we expect surface winds to crank up to 15g25KT from the SW. Winds will eventually veer to the west later tomorrow afternoon, as clouds begin to lift and vis improves to VFR. && .CLIMATE... Issued at 332 AM CST Mon Feb 6 2017 Record high temperatures for Tuesday: Champaign........... 64 in 1925 Charleston.......... 67 in 1925 Jacksonville........ 65 in 1925 Lincoln............. 66 in 2009 Olney............... 69 in 1925 Peoria.............. 65 in 2009 Springfield......... 67 in 2009 && .ILX WATCHES/WARNINGS/ADVISORIES... Dense Fog Advisory until 1 AM CST Tuesday for ILZ027>031-036>038- 041>046-053>057-063. && $$ UPDATE...Shimon SHORT TERM...07 LONG TERM...Auten AVIATION...Shimon CLIMATE...Geelhart
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
1001 PM CST Mon Feb 6 2017 ...SEVERE WEATHER POTENTIAL INCREASING FOR TOMORROW... .UPDATE... Updated for evening discussion. && .DISCUSSION... Weather models over the last 24 hours are generally trying to play catch-up to observations of energy aloft pouring into the Southern Plains. The influx of this jet stream energy into the Lower Mississippi Valley will manifest in the jet`s left exit region enhancing powerful thunderstorm development over at least the eastern half of the region tomorrow, mainly in the mid morning through early afternoon hours. Some storms could begin before sunrise in portions of the Arklamiss Delta and the lack of a solid front to force storms could allow for a few waves of storms to affect certain spots. Still looks like, as mentioned in the previous discussion, that hail and damaging winds will be the largest threats, but certainly at least a few tornadoes (especially across eastern MS) cannot be ruled out. Latest HRRR runs are suggesting locations in South Central and Southeast MS might be set up for several potent supercells from midday through mid afternoon and for that reason the prior hazard graphic has been updated to include the "elevated" threat in those areas too. The timing portion of that graphic was also updated to slightly speed up the anticipated arrival of the main bulk of activity. /BB/ Prior discussion below: Tonight and Tuesday... Abnormally warm temperatures have once again materialized over the area and spread further north where the warm front moved through this morning. Winds have also been quite gusty from the south this afternoon. All of this occurring in advance of a mid level storm system presently gathering strength over the Plains. The system will dig rapidly southeast overnight as a 110 knot 300 mb jet dives out of the Rockies toward the northern Gulf of Mexico. Favored left exit region of the upper jet will lead to strong upper level divergence over the forecast area by early Tuesday morning. Thermodynamically, the atmosphere will be primed for convection as the models show steep lapse rates with MLCAPEs approaching 2000 J/kg. Combining these parameters with the ambient shear suggest a very favorable environment for rotating updrafts and supercell generation. All modes of severe will be in play including the possibility of a few tornadoes. The storms will enter/develop over the far western areas around sunrise Tuesday, move into middle portions by mid/late morning and pass through eastern sections mostly from noon to mid afternoon. Leading to enhanced instability will be another day of strong heating with max temperatures once again pushing well into the 70s./26/ Tuesday Night through Monday... With most of the severe weather threat having passed during the daylight hours on Tuesday, only a slight chance for showers or thunderstorms will remain east of I-55 Tuesday night and Wednesday. Most likely, the atmosphere will have stabilized too much to see any additional precipitation before the cold front finally is pushed through on Thursday. The cold front should only bring a temporary break in the above normal temperatures, as an upper-level ridge builds overhead late in the week and returning southerly flow push maximum temperatures back into the 70s by Saturday. Rain chances return to the forecast on Sunday when the next upper trough digs into the central CONUS. /NF/ && .AVIATION... 00Z TAF discussion: Expect flight categories to trend to MVFR with patchy IFR late tonight as low stratus spreads north through the region. Any fog issues should be limited to MEI/NMM/HBG/PIB and even there dense fog is not likely. Around daybreak through tomorrow morning expect showers and showers to become an increasing possibility in all areas with chances highest at GWO/GTR/CBM/MEI/NMM/PIB/HBG late morning to midday. Ceilings will remain in the MVFR range at best in most areas through early afternoon, but may trend back to VFR before the afternoon is out at at least GLH. Some storms tomorrow could be severe with large hail. /BB/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 61 76 62 77 / 16 80 10 12 Meridian 59 73 61 76 / 15 84 19 19 Vicksburg 64 76 61 77 / 29 70 8 7 Hattiesburg 59 75 62 78 / 9 69 12 15 Natchez 64 76 62 77 / 34 75 8 8 Greenville 63 74 56 73 / 56 79 8 11 Greenwood 62 74 58 73 / 28 84 9 18 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. && $$ NF/26/BB
National Weather Service Jackson KY
1012 PM EST Mon Feb 6 2017 .UPDATE... Issued at 1012 PM EST MON FEB 6 2017 Updated the forecast again to lower precipitation probabilities some more through 5 or 6Z tonight per the latest radar trends and HRRR model run. The bulk of shower and storm activity at this time are occurring along and north of the Ohio River in north central Kentucky and southern Indiana. Anticipate showers increasing in coverage over the next several hours, especially after 6Z, with a few thunderstorms possible as well as the low level jet moves east and strengthens. Also updated the hazardous weather outlook to remove evening wording from it and indicate the potential for a few thunderstorms late tonight. The updated forecast and HWO have both already been issued. UPDATE Issued at 745 PM EST MON FEB 6 2017 Made some adjustments to the forecast for the rest of tonight. Decreased precipitation probabilities across the area for the next several hours per the latest radar imagery and the latest runs of the HRRR and NAM12 models. At this time the HRRR seems to have the best grasp of reality, so the forecast was adjusted more toward that model than the NAM12 through 3Z. After 3Z, continued with a gradual increase in coverage of showers, as the low level jet becomes active. May still see a few thunderstorms later tonight, but took thunder out for now, through roughly 7Z to be exact. Also decreased PoPs a bit later tonight per the latest model data and current trends. The updated forecast has already been issued. && .SHORT TERM...(This evening through Tuesday night) Issued at 359 PM EST MON FEB 6 2017 In the near term we are dealing with scattered showers this afternoon affecting mostly SW portions of the CWA. So far we have not seen much in the way of lightning and therefore have opted to keep isolated mainly in the SW and W portions of the CWA through the afternoon. This is based on the MUCAPE being more confined to those locales. The forecast becomes quite convoluted over the next 48 hours with differing timing with regards to the different forcing features. That said, tonight we see best chances of POPs mainly north of the Mountain Parkway and west of the I-75 corridors. Even though this will be more elevated convection, there is a dryer layer aloft and plenty of shear leaving it open to isolated stronger storms that could produce some small hail. The question here will be does the shear environment end up killing these storms before they can really get going. Now the best LLJ comes late tonight into early tomorrow morning, and the question then becomes how much convection will be able to develop given that much of the northern and western portions of the CWA are potentially worked over. This may be a case where the LLJ can be a focus point early on. The CAMs do show some convection firing up along a 850mb moisture boundary by around 15Z and height falls will continue during this time. Now if any location could see destabilization it would be the far east, but the LLJ jet will have pushed NE of the region by this point. Therefore how much wind could you really mix down and will there actually be a mechanism to drive it. The actual surface front will be trailing as one front undergoes frontolysis, and the next airmass changing cold front approaches by late evening Tuesday into Wednesday morning. Given all this we could see several rounds of showers and perhaps a few thunderstorms and some of these could be strong to severe. The confidence in this forecast is one of the more low confidence forecasts seen in quite some time for a closer range event. Again this is due to the differences in the forcing features and the lack of better surface instability. .LONG TERM...(Wednesday through Monday) Issued at 359 PM EST MON FEB 6 2017 Rain should be tapering off to the east Wednesday morning as the above mentioned cold front moves into eastern Kentucky. Dry conditions should then ensue until the afternoon when an upper low migrates out of the Northwest Territories toward Hudson Bay, bringing a strong enough punch of cold air advection to carve out a trough into the Gulf of Mexico. This will lead to a renewed round of showers and isolated thunderstorms Wednesday afternoon as the previous cold front stalls across the state or northern Tennessee north of a surface low extending from the lower Mississippi River Valley to the Tennessee Valley. Will see this surface low pass into the Appalachians as the upper trough axis swings east, bringing a Canadian cold front into eastern Kentucky ahead of a 1030-1035 mb surface ridge ejecting out of the Great Plains into the Midwest. Leftover precipitation will transition to light snow into Thursday morning, perhaps bringing a light dusting to the Big Sandy region of far eastern Kentucky. Despite slowly clearing skies Thursday afternoon, northwest winds and cold air advection will spell temperatures only topping out in the 30s. A ridge/valley temperature split will then develop underneath the approaching surface ridge Thursday night as valleys drop into the upper teens while ridges remain in the low 20s. A warming trend will then take place into the weekend as flow aloft backs ahead of an upper trough developing off the Pacific coast. A surface low looks to move out of the central Plains Saturday, sending a warm front in vicinity of the Ohio Valley, thus leading to increasing rain chances as temperatures climb back into the upper 50s to near 60 degrees. Another cold front then looks on tap to approach the region late in the weekend as northern stream energy from the newly formed trough pushes through the Great Lakes, bringing cooler and drier conditions for the beginning of next week. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) ISSUED AT 654 PM EST MON FEB 6 2017 MVFR/IFR clouds, with some scattered showers, will move through eastern Kentucky through 06z as a warm front lifts northeast across the area. A low level jet will ramp up across the Ohio Valley overnight, allowing for low level wind shear from 06 to 15z. Clouds will raise up to VFR overnight, before gradually lowering from west to on Tuesday, as a cold front gradually approaches from the west. Showers, along with isolated thunderstorms will move through the area, with temporary MVFR or worse conditions during any passing thunderstorms. Sustained southwest winds of 10 to 15 kts, with gusts of 20 to 25 kts, will engage on Tuesday. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AR SHORT TERM...DJ LONG TERM...GUSEMAN AVIATION...GEOGERIAN
Area Forecast Discussion
National Weather Service Key West FL
932 PM EST Mon Feb 6 2017 .DISCUSSION...In the middle and upper levels(700-200 mb), latest IR imagery overlaid with available model streamline analysis as of 800 pm, depicts a zonal/broadly cyclonic middle and upper flow pattern across the southern CONUS with generalized troughing more evident across the Southern Plains and Western Gulf of Mexico. The southern stream is energetic with 50 to 75 knots at 250 mb upstream over the Southern Gulf as well as over the Keys. At the surface and in the lower to middle levels, latest marine and land surface observations and analysis as of 800 pm, detail a 1020-1025 mb surface ridge oriented from near Bermuda west southwestward to North Florida. The result of this is typical lower level convergent flow across the local area. An embedded lower level undulation is ensconced within this flow now near the Florida Keys and was/is likely causing isolated small showers within 15 nm south of the Florida Reef. As a result, the 00Z sounding illustrated mostly fresh east winds from off the surface up to only about 900 mb, and moisture was limited in the lower to mid troposphere with total columnar PWAT at 1.06 inches. .CURRENTLY...As of 800 pm, skies are partly cloudy across the islands and adjoining waters. Temperatures over the islands are in the mid to upper 70s with dewpoints near 70 degrees. As mentioned above, radar does detects isolated small showers of moderate rainfall just off and parallel to the Florida Reef drifting slowly northwestward at 5 to 10 knots. .SHORT TERM...Overnight, The isolated shower activity is associated with a very subtle wind surge boundary over the Florida Straits, but this is/was not shown in the local mesoscale WRF and HRRR models. At this hour coverage has become very isolated and the undulation possibly appears to be dampening out, but not entirely. Therefore an update was already performed around 700 pm to remove higher rain chances over the lower keys, which were 50%, down to isolated or 20% for all of the Keys and surrounding waters overnight. Still believe there is enough low level convergence to justify the slight chance pops. This is actually below MOS numerical 12 hour pops for the period as well. The strongest winds will remain in the offshore waters well away from the Florida Keys given the current MSLP gradient. As the ridge begins to break down towards morning on Tuesday, local winds will begin to come down. && .MARINE...Overnight, Given decent lower level convergence, strongest winds will remain well offshore, but moreso across the Western Florida Straits away from the Florida Peninsula and the Keys. Given prolonged period of east winds in the last few days, latest available wave model still highlights that seas of 7 feet to remain across the Western Florida Straits thru 12Z. As such, a small craft advisory is already in place across these waters, with cautionary headlines across the rest of the Florida Straits and all of Hawk Channel. Winds and seas will let down on Tuesday, but its likely a cautionary statement will remain in place across the Florida Straits given seas of up to 6 feet remaining. && .AVIATION...Overnight and Tuesday morning, VFR conditions will prevail at both EYW and MTH Int`l terminals thru 12 Zulu with winds from 100 degrees aoa 7-10 knots. Winds will average near 10 knots with gusts near 15 knots from 100 degrees. Expect scattered clouds at FL025-030 AND FL050-070. && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...Small Craft Advisory until 11 PM EST this evening for GMZ054-055- 074-075. && $$ Public/Marine/Fire...Futterman Aviation/Nowcasts....Futterman Upper Air/Data Collection......Vickery Visit us on the web at Follow us on Facebook and Twitter at:
Area Forecast Discussion
National Weather Service Melbourne FL
940 PM EST Mon Feb 6 2017 .DISCUSSION... Tonight...Quiet WX overnight with temps not quite as cool as last night as low level flow veers out of the SE-S. Lows generally in the mid to upper 50s, lower 60s along the treasure coast. The forecast challenge is once again the coverage of fog. Conditions don`t look quite as favorable tonight as SE winds above the boundary increase near 15 knots toward morning. Forecast model soundings also show some altocumulus spreading N/NE overnight, likely resulting from late boundary collision over the FL west coast. Nonetheless, patchy fog will occur, with locally dense fog possible focused on Orange county northward per recent HRRR and local WRF model runs. Tuesday...(previous) Broad short wave over the Central Plains will advect steadily eastward over the next 36hrs...pushing east of the Lower MS Valley by late aftn. This will force the H85-H50 steering flow over the GOMex/FL Peninsula to veer to the S/SW thru the day, which in turn will pull a remnant frontal moisture band up from the FL Straits back into central FL...PWat values increasing to 1.00"- 1.25" by late aftn. RAP analysis picking up a band of enhanced H85- H30 vorticity extending from central FL into the central GOMex that also will be tapped by the dvlpg SWrly flow. Mid lvl thermal profile increasingly unstable upstream with an H70 thermal trof over the NE GOMex dropping temps as low as 2C...H50 temps btwn -10/-12C. The 06/12Z RAOBs showed a steady erosion of an H85-H70 subsidence inversion over central FL from the 05/12Z flight...RAP analysis confirms this with lapse rates increasing from 4.5-5.0C/KM over the central peninsula to 7.0-7.5C/KM over the central GOMex. Given the WX elements in play, chc aftn convection will remain in the fcst. Given the SW steering flow and potential for weak coastal convergence, will go with 40pct coastal PoPs from Brevard Co southward...30pct interior and coastal Volusia. Cannot rule out an isold tsra especially should max temps reach the fcst convective triggers (U70s/L80s)...not unlikely given the anticipated S/SW flow. && .AVIATION... Patchy IFR/MVFR VSBYs developing aft 06Z especially MCO northward. On Tue...South to southeast winds 10-15 knots with scattered SHRA and possibly a few TSRA mainly during the afternoon. && .MARINE... No significant changes to current coastal waters forecast. Tonight-Tuesday (modified)...Hi pres ridge over N FL will push into the Atlc overnight and merge with the Bermuda Ridge axis east of the Bahama Bank by daybreak. A light E/NE flow this eve will veer to SE overnight. On Tue, a gentle to moderate S/SE breeze 10-15 knots will produce seas 2-3FT nearshore and 4FT offshore. && .PRELIMINARY POINT TEMPS/POPS... DAB 59 80 60 80 / 0 30 30 10 MCO 60 82 61 83 / 0 30 30 10 MLB 62 80 61 81 / 0 30 30 10 VRB 63 80 59 82 / 0 30 30 10 LEE 59 81 62 83 / 0 30 20 10 SFB 59 82 60 83 / 0 30 30 10 ORL 60 82 62 83 / 0 30 30 10 FPR 62 80 58 82 / 0 20 30 10 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$ Kelly/Weitlich
Area Forecast Discussion
National Weather Service Norman OK
855 PM CST Mon Feb 6 2017 .DISCUSSION... Still 18 degrees above the normal daily high temperature at 9 PM, temperatures are not falling as quickly as forecast. The trend from the HRRR are much more realistic and have been used to populate the overnight temperature grids. The dense cirrus over the central part of Oklahoma is expected to move mostly east and out of the area before sunrise. No other changes appear necessary at the moment. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 45 77 42 63 / 0 0 0 0 Hobart OK 45 76 42 68 / 0 0 0 0 Wichita Falls TX 48 77 46 71 / 0 0 0 0 Gage OK 38 74 35 63 / 0 0 0 0 Ponca City OK 41 75 36 55 / 0 0 0 0 Durant OK 57 78 49 72 / 10 0 0 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...None. TX...Fire Weather Watch Tuesday afternoon for TXZ083>090. && $$ 09/10
Area Forecast Discussion
National Weather Service Paducah KY
928 PM CST Mon Feb 6 2017 UPDATE... Issued at 928 PM CST Mon Feb 6 2017 Updated aviation discussion for rapid cig changes. && UPDATE...Issued at 801 PM CST Mon Feb 6 2017 Numerous showers over southwest Indiana and southeast Illinois will continue to lift north out of our region in the next hour or two. Elsewhere, only a smattering of light showers is noted on radar. Latest HRRR guidance indicates that scattered showers and thunderstorms should pick up over the region after 10 PM, and then become most numerous overnight over west Kentucky. 18Z NAM soundings indicate that deep instability is not likely to develop until after 03Z, but that significant positive area is available to an elevated parcel based around 850mb. Although coverage may remain more scattered than numerous, the threat for large hail is still valid. With upwards of 50kts just off the surface, a stray damaging wind gust cannot be ruled out at this time. Despite very strong shear forecast in the 0-1km layer, the elevated nature of tonight`s convection should make tornadoes a very slim (but not zero) prospect. Made adjustments to PoP/Wx trends through the night to account for the evolution described above. The HWO seems to be on track. && .SHORT TERM...(Tonight through Tuesday night) Issued at 220 PM CST Mon Feb 6 2017 The primary concern through Tuesday is thunderstorm potential. A southerly low-level wind flow is forecast to increase through the night, up to around 60 knots at 850 mb. The low-level inversion is forecast to hold tough in most areas, which should keep surface gusts mainly under 35 mph overnight. Elevated instability will increase tonight, setting the stage for numerous showers and storms. The models forecast mucapes to increase to 1000 j/kg or better late tonight, and mid-level lapse rates will be around 8 c/km. This looks like a favorable setup for hail, and isolated large hail is possible. Most guidance indicates surface- based instability will develop over se Missouri tonight, which is why the threat of an isolated tornado has been included in the HWO and multi-media briefing. On Tuesday, the widespread convective activity associated with the warm advection pattern and low-level jet will diminish in the morning. A surface cold front is then forecast to move east across the Lower Ohio Valley in the afternoon. Storms could redevelop along the front in the afternoon, but there will be some factors inhibiting development. The first and foremost factor will be possible subsidence in the wake of a 500 mb shortwave that will cross our region during the day. The accompanying dry air in the wake of the shortwave causes model K-indices to fall below 20 in the afternoon in many areas. Another inhibiting factor is weak low-level convergence near the front as winds veer west-southwest ahead of the front. However, model capes are quite impressive as surface heating should raise temps to around 70 in the afternoon. One of the main determining factors should be the amount of clearing and solar heating. A good deal of sun would result in stronger instability, and there will be a shallow layer of moisture with surface dew points near 60. Shear profiles will be supportive of severe potential in any storms that develop. A slight risk of severe storms is forecast mainly east of the Mississippi River. Any lingering convection in western Kentucky early Tuesday evening will end as the cold front passes to our east. Temps will fall back into the 30s and 40s overnight Tuesday night. .LONG TERM...(Wednesday through Monday) Issued at 220 PM CST Mon Feb 6 2017 The see-saw temperature pattern will continue during the long-term period. Cold high pressure will build southeast from the Canada on Wednesday to the Lower Ohio Valley by Thursday night. This high will bring a relatively quick shot of cold air, along with mainly dry conditions Wednesday through the end of the week. It may be difficult to get rid of the lower stratus cloud deck on Wednesday and Wed night, which may have a profound effect on surface temps. Still think most locations will be down into the 20s though both Wed and Thu nights. Winds will turn back to the south by the weekend as the high moves east and another low pressure system passes north and west of our region. This will result in a fairly rapid warm up Sat into Sun. A cold front trailing the system will then drop into the Ohio Valley by the end of the weekend, bringing the next good chance of rain with it. Will leave mention of thunder out for now, as instability looks quite meager at this point. && .AVIATION... Issued at 928 PM CST Mon Feb 6 2017 Cigs in the warm sector have gone, or will probably go, VFR this evening over most of the region. Rain shower clusters will continue to move rapidly east-northeast this evening. Some thunderstorm activity will be around overnight, and the lift associated with this convection may provide IFR cigs late in the night. Strong southerly low-level winds aloft will result in some surface gusts to 25 knots overnight. On Tuesday morning, cigs and vsbys will improve markedly as precipitation diminishes from the west. Winds will turn into the southwest and stay rather gusty. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...None. MO...None. IN...None. KY...None. && $$ UPDATE...DRS SHORT TERM...MY LONG TERM...GM AVIATION...DB
Area Forecast Discussion
National Weather Service Mount Holly NJ
923 PM EST Mon Feb 6 2017 .SYNOPSIS... Low pressure is forecast to pass across the Great Lakes on Tuesday and it should traverse Quebec on Wednesday. The low is expected to pull a warm front through our region on Tuesday followed by a cold front on Wednesday. An area of low pressure is anticipated to develop along the cold front and it should pass off the Middle Atlantic coast early on Thursday. High pressure is forecast to follow for Friday into Saturday. Another area of low pressure is expected to move across the Great Lakes on Sunday and into southeastern Canada on Monday. The low is anticipated to pull a warm front through our region on Sunday followed by a cold front on Sunday night. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Complex trough moving through the northern Rockies and Great Plains at this time is contributing to ongoing cyclogenesis in Kansas. These features will progress rapidly within the fast polar jet across the northern U.S., with the surface low expected to reach western Illinois by 12Z Tuesday. Dynamic lift associated with a 150+-kt 250-mb jet streak in the northern Rockies will aid in the deepening of the low. Combined with sustained isentropic ascent on the upstream side of the surface high moving into the western Atlantic this afternoon, a region of deep lift will contribute to the development of widespread precipitation in much of the Mississippi and Ohio Valleys this evening and tonight. Anticyclonic flow in the eastern U.S. will spread this precipitation into the Mid-Atlantic after midnight. Strongest lift/dynamics look to remain west of the region, with the proximity of the surface high in the Atlantic precluding more substantial precipitation from occurring in our CWA. Nevertheless, at least light precipitation looks to spread into SE PA/NE MD around 08-09Z with an initial band on the leading edge of the strong low-level isentropic ascent (and a low-level jet stream). High-resolution guidance is reasonably similar with timing this precipitation but varies widely regarding intensity, with WRF simulations on the wetter side and the HRRR on the drier side. Current thinking is that the drier solutions are more likely given the residual near-surface dry air from the aforementioned Atlantic surface high. A second band will approach the region by daybreak tomorrow, which appears more closely tied with the leading vorticity maximum associated with the progressive trough. Given the stronger dynamics in play with this perturbation, this second band is expected to be the main show. The RAP is considerably drier than the WRF simulations with this second round in our area. With this second band, the forecast is more uncertain, as models tend to struggle with the localized (usually strong) lift these small- scale perturbations can provide. Temps have fallen quite a bit over nrn and wrn areas with Mt. Pocono dropping below freezing, before rising to 32. Parts of Nrn NJ remain below freezing. Latest HRRR slows down onset time of precip until the 08/09Z time frame. So, have lowered or removed pops earlier than that. A slower onset will have potential ramifications on headlines as there could be less qpf to fall over the subfreezing temps. No headline changes are planned attm, but will continue to monitor and see what other mdls do as well. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/... As the surface low near Illinois continues its trek northeast to the Great Lakes and adjacent southeast Canada by 00Z Wednesday, continued warm air advection will promote warming temperatures across the CWA during the day, with any remaining freezing rain in the southern Poconos likely over by mid morning. The main band of precipitation is expected to move through during the morning hours, with best chances north of the Mason-Dixon Line -- areas to the south may see little or no precipitation based on the latest RAP solutions. Total QPF looks to be around a quarter of an inch north of I-78, about 0.1-0.25 inches between I-78 and the Mason-Dixon Line, and less than a tenth south of there. Rain looks to become spottier/more showery by late in the day. Temperatures will be well above average for this time of year, with highs about 2-7 degrees warmer than those seen today, as the CWA remains positioned in the warm sector of the storm system through sunset. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... It looks as though the mid level pattern will be quite progressive during the period from Tuesday night through Monday. A mid level short wave trough is forecast to pass over our region on Tuesday night. It will bring a continuing possibility of rain showers at that time. The chance of rain showers is expected to diminish on Wednesday in the wake of the short wave. The cloud cover may decrease a bit at that time. A cold front is anticipated to approach from the northwest. A mild southwesterly flow in advance of the boundary is expected to bring some record warm temperatures to parts of our region. A list of the record high temperatures for February 8 is found below in the climate section of this discussion. Things continue to get interesting for Wednesday night into Thursday. A surface wave of low pressure is anticipated to develop along the cold front and it is forecast to pass off the Middle Atlantic coast early on Thursday. Meanwhile, strong cold advection should begin to take place in our region. Even though temperatures should be well into the 60s in much of our region on Wednesday, they are forecast to drop into the 30s on Wednesday night and they should stay in that range on Thursday. Readings are forecast to be in the 20s in our northern counties. A mid level trough is expected to approach from the west on Thursday with its axis passing overhead early on Thursday night. The enhanced lift ahead of the feature along with the moisture associated with the surface low should bring us another shot of precipitation from late Wednesday night into Thursday morning. The precipitation is expected to change from rain to snow from south to north across eastern Pennsylvania, New Jersey, Delaware and northeastern Maryland. We will post the snowfall forecast map for the Wednesday night into Thursday event on our web site. Generally, we are anticipating 2 to 5 inches in eastern Pennsylvania and northern and central New Jersey and an inch or two from the upper Delmarva into parts of southern New Jersey. The snowfall amounts in our far southern counties should be less than an inch. The snowfall forecast is not one of high confidence at this point. There are some tricky timing issues regarding the arrival and departure of the precipitation and the rate of the cold advection. As a result, there is a fairly wide spread in the potential outcome of the event as depicted in the winter weather section of our web site. A typical cold advection pattern is anticipated for Thursday into Friday as high pressure passes to our south across the southeastern states. We are expecting some stratocumulus along with a chance of snow showers, mainly in our northern counties. Another low is forecast to pass well to our northwest over the weekend and it should pull a warm front through our region on Sunday followed by a cold front on Sunday night. We have the mention of precipitation. Temperatures should support mostly rain at that time. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Ceilings are expected to lower to MVFR in the 06Z to 10Z time frame as areas of rain move in from the southwest. IFR ore even LIFR conditions may occur during the heaviest precipitation, especially given a pronounced inversion just above the surface. KMIV and KACY may avoid most of the precipitation, with a chance that sub-VFR conditions never occur. Conditions are expected to improve to VFR region wide by late afternoon. Winds will change to light southerly or southeasterly tonight, returning to a more southwesterly direction by late Tuesday afternoon. Outlook... Tuesday night...There is the potential for rain showers along with some localized MVFR and IFR conditions. Also, there may be low level wind shear as a low level southwesterly jet is forecast to be located over our region. Wednesday...Mainly VFR with a chance of showers. Wednesday night and Thursday morning...Conditions deteriorating into the IFR category in rain changing to snow. Thursday afternoon...Conditions improving to VFR. Thursday night through Saturday...Mainly VFR. && .MARINE... A storm system moving through the Great Lakes and southeast Canada over the next 24 hours will bring increasing southerly to southwesterly winds to the marine zones by late Tuesday morning. Winds look to increase above advisory thresholds from south to north, so moved up the start time of the advisory for the coastal Atlantic from Cape May to Fenwick Island to 10 am Tuesday. Seas will build during the day Tuesday, with 3-7 foot seas common by late in the day. Looks like the strongest winds will hold off until Tuesday evening for Delaware Bay. A chance of rain exists for much of the day Tuesday, especially along the coast of New Jersey. Outlook... Tuesday night and Wednesday...Small Craft Advisory conditions continue on Delaware Bay until 1:00 AM Wednesday, for our ocean waters off Delaware until noon on Wednesday, and for our waters off New Jersey until 6:00 PM Wednesday. Wednesday night...No marine headlines are anticipated. Thursday through Friday...Northwest wind gusts of 25 to 30 knots are possible. Friday night and Saturday...No marine headlines are anticipated. && .CLIMATE... Temperatures may reach or exceed record highs on Wednesday in several areas with highs in the 50`s across northern New Jersey and northeast Pennsylvania. Highs further south will be in the low to mid 60`s. Here are the past records for 2/8. Philadelphia and Trenton are projected to break the record highs. Wilmington,Trenton and Georgetown have the best chance to approach but not exceed record highs. Altantic City 69 in 1965 Philadelphia 63 in 1925 Wilmington 66 in 1965 Allentown 59 in 1965 Trenton 62 in 1933 Georgetown 69 in 1965 Reading 63 in 1965 Mount Pocono 48 in 2000 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...Freezing Rain Advisory from 1 AM to 10 AM EST Tuesday for PAZ054-055-062. NJ...Freezing Rain Advisory from 1 AM to 10 AM EST Tuesday for NJZ001-007. DE...None. MD...None. MARINE...Small Craft Advisory from noon Tuesday to 6 PM EST Wednesday for ANZ450>453. Small Craft Advisory from 10 AM Tuesday to noon EST Wednesday for ANZ454-455. Small Craft Advisory from 6 PM Tuesday to 1 AM EST Wednesday for ANZ430-431. && $$ Synopsis...Iovino Near Term...CMS/Nierenberg Short Term...CMS Long Term...Iovino Aviation...CMS/Iovino/Nierenberg Marine...CMS/Iovino Climate...
Area Forecast Discussion
National Weather Service Raleigh NC
830 PM EST Mon Feb 6 2017 .SYNOPSIS... High pressure over the western Atlantic will bring southwesterly flow and warmer air to central NC through Tuesday ahead of a frontal system that will cross the area on Wednesday. && .NEAR TERM /THROUGH TONIGHT/... As of 300 PM Monday... A few sprinkles across the west on radar are likely to dissipate as they move to the east. Current run of the HRRR model has some continued sprinkles for the next several hours before drying out after 6z. The bigger impact however will be to aviation conditions as some MVFR ceilings are possible in the west as low level moisture begins to move in. Ceilings aren`t expected to develop until closer to daybreak however. The timing of these ceilings could affect the low temperatures and therefore should be a few degrees warmer in the west as opposed to points east which should remain clear for longer. Low to mid 40s expected for lows. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... As of 300 PM Monday... Tuesday, a deep sw flow will advect a warm and increasingly moist air mass into our region. Afternoon low level thickness values are projected to be 1368-1373m, a solid 45-50m above normal and supportive of afternoon temperatures near 70-lower 70s. While skies will not be totally sunny, a mixture of sun and clouds, allowing for at least some partial sunshine. A tightening pressure gradient between an area of low pressure lifting ne across the mid MS Valley, and an area of high pressure off the Southeast U.S. coast will result in breezy sw winds Tuesday. Gusts 20-25 mph will be common. Tuesday night, a s/w in the southern stream will pass to our south. This system will induce modest upper divergence aloft, leading to a threat for a few showers, primarily south of highway 64. Lift through the column not all that deep and models have begun to trend drier during this period, so will cap PoPs around 30% with most locations only seeing a 1:5 shot of getting measurable rain. Considerable cloudiness and a steady sly wind will result in overnight temperatures closer to our normal daytime highs for this time of year. Min temps generally in the mid 50s. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... As of 230 PM Monday... Wednesday and Thursday: Models continue to trend drier for the system Wednesday/Thursday. The shortwave that passes over the region Tuesday night will shift offshore on Wednesday, with westerly to west-southwesterly flow aloft over Central NC. Some light rain cannot be ruled out during this time, although it`s looking less and less likely with time. The upper level trough will amplify Wednesday night, digging into the Carolinas by Thursday. The associated cold front will approach from the north Wednesday evening/night, though the models show a surface low sliding northeastward along the front overnight, moving out over the Atlantic Thursday morning. This surface low will enhance the warm southwesterly flow into the region on Wednesday, resulting in highs ranging from mid 60s to low 70s across the area. Also, the best chance for appreciable rainfall will be when the low is in closest proximity to Central NC, although it could split the area entirely. The speed at which the low moves out of the region will determine how quickly the effective front slides through Central NC. There are still timing differences between the models, thus confidence is not high with respect to fropa timing. However, expect the front to move through the area by late Thursday. The strongest cold air advection will lag behind the fropa several hours, with the main surge not expected until late Thursday. Winds will be strong and gusty with the front, decreasing to light and variable overnight. With the rapidly clearing skies and abating winds, Thursday night lows will drop like a rock into the mid to upper 20s. Friday through Monday: Surface high pressure will approach, move through, and shift offshore of the Carolinas while the upper level ridge amplifies. As a result, dry weather and a warming trend is expected for this part of the forecast period. Highs will be cool on Friday, mainly in the 40s. Temperatures will begin to moderate again Friday night through Monday, rebounding back to highs in the 60s/70s by Monday. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... As of 717 PM Monday... Strengthening sly low level flow will advect moisture into the western Piedmont, leading to the development of stratus and associated MVFR ceilings between 10 to 12z. Additionally, some of the model guidance suggest an area of fog developing across the far southeastern zones. However, given the broken high clouds overspreading the area from the from the west, believe this is a bit overdone. For now will include a tempo group for MVFR fog between 11 to 13z at KFAY only. Any sub VFR ceilings that develop in the west (KINT and KGSO) will likely linger through late morning/mid day. In addition, it will become breezy Tuesday with gusts 20-25 kts likely across central NC during the afternoon. The probability for sub VFR ceilings will persist and likely increase late Tuesday night through early Thursday as a series of upper disturbances and attendant surface waves cross the region. At this time, expect the highest concentration of showers, and possibly a few thunderstorms, to occur late Wednesday into Wednesday night. Sub VFR ceilings still probable early Thursday though improving aviation conditions and a return to VFR parameters anticipated for Friday and Saturday. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Ellis NEAR TERM...Ellis SHORT TERM...WSS LONG TERM...KC AVIATION...CBL/WSS
Area Forecast Discussion
National Weather Service Springfield MO
527 PM CST Mon Feb 6 2017 ...00z Aviation Update... .SYNOPSIS... Issued at 242 PM CST Mon Feb 6 2017 A stout south-southwest wind today has helped temperatures warm into the mid 60s to around 70 across the CWA this afternoon and has also transported Gulf moisture northward, with surface dewpoints in the mid to upper 50s. The cloud cover has prevented temperatures from reaching the lower to middle 70s. The surface warm front bisected the CWA from northwest to southeast across central and south central MO, extending westward back to the area of low pressure over western KS. A dry line extended south out of the low into western OK and into west TX. Aloft, there was a trough across the high plains with shortwave energy approaching the area from the west/southwest. Models were indicating a thermal capping inversion currently in place over the warm sector. Main forecast focus in the short term will be with convective initiation and the potential for severe weather this evening/tonight. && .SHORT TERM...(This evening through Tuesday) Issued at 242 PM CST Mon Feb 6 2017 Models have struggled in recent runs with developing convection today/tonight over the CWA despite the decent CAPE and lead shortwave energy which should approach early this evening. Models do begin to erode the cap by mid evening and we could see a few storms begin to develop as early as 7 - 8 pm this evening. With the increased CAPE and 40-50 kts of bulk shear, large hail will be the main severe weather risk. Can`t rule out some damaging wind or even a tornado, but the main risk will be with large hail...if things develop. The latest HRRR is not developing anything until the front and main shortwave begin to push through very late tonight. So this will be a conditional risk if storms can get going, some will probably be strong to severe. The main wave should kick through on Tuesday morning, shifting the convection and severe potential into the MS/OH/TN valley regions for Tuesday. Temperatures will remain mild on Tuesday, even behind the shortwave with highs climbing back into the 60s and 70s. .LONG TERM...(Tuesday Night through Monday) Issued at 242 PM CST Mon Feb 6 2017 A stronger push of the colder air mass will not arrive until Wed/Wed night as a strong upper jet streak shifts east-southeast into the central U.S. Canadian high pressure will drop southeast into the forecast area and we should see temperatures still above normal for Wednesdays highs, but about 10 to 15 degrees cooler than today/Tuesday. But, by Wed. night we should see lows dipping back into the low to mid 20s. Highs on Thursday will only be in the upper 30s to upper 40s as the Canadian high shifts across the area. As the high slides to the southeast of us by late in the week, we should see a return to strong southerly flow and low level warm advection with ridging building back into the area aloft. That should warm us back up into the 60s/70s on Friday/Saturday. Next chance at precipitation will be late in the weekend as another frontal boundary approaches and moves through. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 527 PM CST Mon Feb 6 2017 VFR conditions likely with MVFR conditions possible through tonight and into early Tuesday. Isolated showers/t`storms can`t be ruled out, especially over the SGF and BBG terminals later this evening and overnight. Given the isolated nature, went ahead and only kept VCs in to cover. LLWS will also increase tonight as a low level jet begins to take shape. Cloud cover should begin to dissipate by mid to late morning Tuesday. VFR conditions can be expected from then until the end of this forecast period. && .CLIMATE... Issued at 1216 PM CST Mon Feb 6 2017 Record warmth is possible across the area on Tuesday. Here are the current record high temperatures across the area for February 7th... Record High/Year Forecast High Springfield74/2015 70 Joplin72/2015 70 West Plains 68/2015 72 Vichy-Rolla 68/2015 68 && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ SYNOPSIS...Lindenberg SHORT TERM...Lindenberg LONG TERM...Lindenberg AVIATION...Frye CLIMATE...Griffin
...Update to aviation forecast discussion...

.SHORT TERM...(This evening through Tuesday) Issued at 301 PM CST Mon Feb 6 2017 Embedded shortwave trough was seen rotating through the central plains this afternoon, as seen on the water vapor imagery. Satellite and observation trends show the warm front centered west to southeast just south of the I 70 corridor. Dewpoints in the 50s are observed over east central areas with periods of patchy fog and drizzle through early evening. Further north of the warm front towards north central Kansas, the fog thickness has remained with dewpoint and temp depressions near 0. This has kept highs cooler in the upper 40s, while middle to upper 50s are observed elsewhere. Some uncertainty on timing of clouds clearing tonight with visible imagery showing some breaks in the clouds over south central KS currently. Latest hrrr guidance would have the drier air moving into eastern KS by 00Z tonight. As the upper trough lifts eastward overnight, residual low level moisture on the backside of the departing low may linger the low stratus and patchy fog through sunrise Tuesday. Sfc trough deepens over the western high plains Tuesday, surging a cold front southward into the CWA in the mid to late afternoon. Timing of the front and the surge of cold air behind it vary from the GFS to the NAM and SREF, leading to uncertainty in temps especially along and south of Interstate 70. Overall stuck to persistence while following the MAV and MET guidance which favors a tight gradient from the upper 60s in far east central KS, to near 50 degrees near the Nebraska border. Fire weather concerns remain minimal given the light westerly winds at 10 to 15 mph in the afternoon. RH values at peak mixing down to the lower 30 percentile. .LONG TERM...(Tuesday night through Monday) Issued at 301 PM CST Mon Feb 6 2017 Front continues to push southward Tuesday night into Wednesday, keeping the boundary layer mixed, but still dropping lows into the 20s with highs rising into the 30s to 40s. Could see some very light snow along the northern border Tuesday night as frontogenesis brings some lift across in the overnight hours. Wednesday night bodes a little cooler with lows in the teens as the center of the high moves into the northern CWA by sunrise. It advects eastward under the NW flow aloft, with southerly surface winds returning by late Thursday, which should bring highs back into the 30s and 40s once again. Warmer lows Thursday night in the 30s. Friday and Saturday shaping up to be a pretty nice end to the week with southwest surface winds and warm advection bringing highs into the 60s for Friday. Next front moves into the far northern CWA late in the day Saturday, but highs still reach 50s and 60s before the front drops south. Air behind the front isnt all that cold however, and highs still rise into the 40s to low 50s for Sunday and Monday. Outside chance for some precipitation late Saturday into early Sunday as the front comes through. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 541 PM CST Mon Feb 6 2017 For the 00Z TAFs, expecting that periods of MVFR CIGS will be in and out during the next 6hrs as wrap around stratus moves through the terminals. Winds remain generally under 10kts the entire period and slowly veer to the northwest by morning and afternoon time frame on Tuesday. Could see some slightly reduced VIS during the 12Z time frame as just enough low level saturation occurs behind the slow moving system, but not expecting reductions much below MVFR category as dry air continues to filter into the area. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Prieto LONG TERM...67 AVIATION...Drake
Area Forecast Discussion
National Weather Service Tulsa OK
903 PM CST Mon Feb 6 2017 ...UPDATE... .DISCUSSION... Severe thunderstorm threat will persist into the overnight hours across portions of northwest Arkansas and far northeast Oklahoma generally along and east of a Talihina, Stilwell, Bentonville line. Area of enhanced mid/high clouds moving through central Oklahoma in association with approaching wave. 00Z NAM run including latest HRRR suggest isolated storms will develop very near or just of east of the CWA around midnight. Moderate instability coupled with strong deep layer shear suggest any storms that develop could produce very large hail, especially given the steep mid level lapse rates/cold temperatures aloft. Thunderstorm activity is expected to remain slightly elevated which would limit the tornado potential but latest trends will need to be monitored very closely given the strong low level winds fields and low LCL heights. With all that said, current forecast generally on track this evening with only minor changes anticipated. Update out shortly. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...None. AR...None. && $$ SHORT TERM...12