Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/05/19

National Weather Service Wakefield VA
954 PM EST Mon Mar 4 2019 .SYNOPSIS... A weak trough will track across the region tonight, then weak low pressure will track east northeast and out to sea Tuesday into Tuesday night. Cold high pressure then builds back into and over the region Tuesday night through Wednesday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... As of 950 PM EST Monday... Strong ~980mb low pressure is located new Newfoundland this evening, with the associated cold front now well off the east coast. Meanwhile, a 1034mb arctic high is centered over the central and southern plains. mostly cloudy to overcast over the Ches. Bay and northern/central coastal waters this evening. This appears to be associated with the combination of a weak sfc trough and a low- level theta-e axis, which is lingering across the local area. Moisture is proving to be too shallow to yield any pcpn, and hi-res guidance has backed off with bringing any measurable PCPN to the coastal zones this evening. Accordingly, have dropped PoPs for the overnight, though a quick sprinkle or flurry cannot be completely ruled out over the next 2-3 hours from the middle peninsula to the VA eastern shore. Temperatures have already dropped into the upper 20s to low 30s where sky has remained mainly clear out in the piedmont and over MD zones of the eastern shore. Therefore dropped temps a bit away from the Bay and coastal zones where clouds will linger overnight. Look for overnight low temperatures to range from the low-mid 20 NW to low 30s SE. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... As of 400 PM EST Monday... The srn stream low/shortwave trough slides ENE off the coast Tuesday. Partly sunny N to mostly cloudy S. The 12z GFS is most aggressive at bringing some light rain nwd into NE NC/far SE VA, but given rather dry conditions PoPs are ~20% at most, mainly for light rain, but a brief light rain/snow mix is possible early. Highs Tuesday will range from around 40F over the Lower MD/VA Ern Shore, to the lower/mid 40s inland W of the Chesapeake Bay. Clearing and cold Tuesday night, as the modified arctic high to the west begins to shift east. Lows will mainly range from the upper teens to the mid 20s. Although below normal, not to record values (see climo section below). Mostly sunny but unseasonably chilly Wednesday. Highs only range from the mid 30s to around 40F. Coldest night will be Wednesday night, as the ridge axis approaches from the west. Lows range form the upper teens to lower 20s, mid 20s SE coast. Again, not to record values. Mostly sunny and continued cool Thursday with highs in the low/mid 40s (upper 40s far S). && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... As of 330 PM EST Sunday... Weak shortwave aloft (coupled w/ a weakening area of sfc low pressure) approach the area from the W Thu night-Fri. Still some disagreement in the models regarding the onset of light pcpn Thu night. GFS continues to show -SN entering the W/NW Piedmont after 06z Fri before pcpn overspreads the entire area from W to E between 12-18z Fri. The ECMWF/CMC are forecasting the pcpn to hold off until the midday-aftn hours on Fri. The ECMWF/CMC scenario would result in mainly RA throughout the area (with a RA/SN mix possible N/NW at the onset of the event). Continued to go with a consensus of the models, which would suggest a light RA/SN mix across the N/NW with -RA elsewhere (w/ all pcpn changing to RA after 15z Fri). Kept PoPs aob 30% through 18z Fri. Models are more in agreement that -RA will continue throughout the area from Fri aftn-late Fri evening (especially south/east). Still some uncertainty about the exact timing, so kept PoPs aob 50% from 18z Fri-06z Sat. Drying out by 12z Sat as the weak low pressure system moves offshore and a weak cold front stalls just S of the CWA. Lows Thu night range from the upper 20s NW to the mid-upper 30s SE. Highs Fri range from the mid 40s NW to the low 50s S/SE. Dry (and near average) on Sat as weak upper ridging briefly moves over the ern CONUS. A strong area of low pressure tracks from the Plains to the Great Lakes from Sat-Sun. This will allow the cold front that stalled just south of our CWA to move back N as a warm front on Sat night-Sun AM. The warm front will quickly surge N of the CWA by midday Sun. Showers are expected to overspread the area from W to E Sun AM. Heavier showers will be possible from Sun aftn- Sun evening as the associated cold front approaches from the WNW. Models are hinting at some sfc- based instability Sun aftn/evening from srn VA to NE NC as temperatures could warm up to near 70 in spots (as dew points rise to near 60). Did not add thunder to the grids attm, but may need to do so in upcoming forecast packages. Drying out late Sun night-Mon as the cold front clears the area. The airmass behind the front will not be as cold as the one that is progged to enter our area during the middle of this week. Highs on Sat are expected to be in the 50s to near 60 in most areas. Forecast highs on Sun range from the upper 50s N/NW to the mid-upper 60s over SE VA/NE NC. Highs still in the upper 50s-mid 60s on Mon. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... As of 630 PM EST Monday... Weak low pressure is centered just to the E of RIC early this evening as an area of CU/SC (~4-5k feet) extends from central VA to NE NC. Some of the hi-res guidance continues to show a small area of very light pcpn developing over east-central VA between now and 03z. However, the latest runs of the HRRR keep the area dry (so confidence in the pcpn developing is low- moderate). If this area of pcpn forms, it will slowly drop SSE into SE VA through 03-06z, before dissipating thereafter. This should mainly be light rain, although a light rain/snow mix is possible. Removed any mention of pcpn from RIC, but kept VCSH in the TAFs for ORF/PHF. CIGS should mainly be around ~4k feet, although brief MVFR CIGS are possible later this evening into the early overnight hours over SE VA/NE NC. Weak low pressure tracks off the Southeast coast Tuesday bringing additional cloud cover to the terminals, but VFR conditions are expected to prevail (CIGS will be in the 3-5k ft range over SE VA/NE NC through much of the day on Tue). Expect mid-high clouds at RIC/SBY from late tonight through 18z Tue before SKC conditions prevail during the remainder of the aftn/evening. Winds remain aob 12 kt through the 00z TAF period. Dry and mostly clear/sunny conditions are expected Tuesday night through Thursday. Another low pressure system approaches from the W Friday and this could bring unsettled conditions later Friday into early Saturday. && .MARINE... As of 930 PM EST Monday... Cancelled SCAs for all ocean zones as seas have fallen to 3.5-4.5 feet as per buoy obs. Seas will continue to slowly diminish through the remainder of the night. Previous Discussion: Improving conditions this afternoon across the marine zones. Winds have dropped to 5-15 knots in the Bay and 10-20 knots offshore and will continue to decrease through the evening. Waves are running 1-3 feet and will become 1-2 feet this evening. Seas will be a little slower to drop with current seas 4-6 feet, becoming 3-5 feet overnight. SCA headlines remain in effect through late tonight for the offshore zones but areas south of Cape Charles Light could fall below thresholds by mid evening as seas subside. Models are picking up on a subtle NNW surge tonight with winds increasing back into the ~15 knot range for a few hours prior to daybreak. Winds are forecast to stay below SCA limits and no new headlines are planned with this package. Generally quiet marine conditions are expected for the daylight hours of Tuesday as weak low pressure passes to our south across the southern Carolinas. A period of enhanced northwesterly flow will ensue late Tuesday night into Wednesday as a dry cold front crosses the region and high pressure builds toward the area. Another round of Small Craft headlines appears likely from late Tuesday night into early Wednesday afternoon. && .HYDROLOGY... As of 345 PM EST Monday... Despite the level at Sebrell below flood state attm, the warning will remain in effect based on Sun night`s rainfall taking it back above flood stage this evening. Otherwise, expect rises on most rivers over the next few days due to Sun night`s rainfall. See FLSAKQ for details. && .CLIMATE... Record low temps: Wed 3/6 Thurs 3/7: RIC...15 in 1960 12 in 1960 ORF...20 in 1901 17 in 1899 SBY...13 in 1978 11 in 2015 ECG...20 in 1960 20 in 1960 Record low max temps: Wed 3/6 RIC...28 in 1901 ORF...28 in 2015 SBY...31 in 2015 ECG...34 in 2015 && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...None. && $$ SYNOPSIS...TMG NEAR TERM...AJZ/MAM SHORT TERM...AJZ/TMG LONG TERM...ERI AVIATION...AJZ/ERI MARINE...ERI/RHR HYDROLOGY... CLIMATE...
Area Forecast Discussion
National Weather Service Caribou ME
1052 PM EST Mon Mar 4 2019 .SYNOPSIS... Low pressure will continue to pull away overnight. High pressure will follow into the region on Tuesday with colder weather through mid-week. && .NEAR TERM /THROUGH TUESDAY/... 1030 PM Update... Radar showing last round of snow moving to the east. The latest HRRR and NAM12 aligning quite well w/the placement. Looks like steadier snow will be winding down after midnight w/some snow showers hanging in overnight, mainly across the north and west. Any additional snowfall accumulation will be < an inch. Temps were holding up in the 20s across the CWA. Colder air still residing back across Quebec. Will need the upper trof to swing across the region to bring that colder air into the region. This is expected to take place overnight w/temps dropping off as skies partially clear out. Previous Discussion... Once snow mvs into NB, winds turn WNW drawing in cldr dwpt temps. Skies rmn cldy acrs the north thru most of the ovrngt with Downeast areas moclr tonight. Temps wl drop into the single digits acrs the north with low teens for Downeast areas under fresh snowcover. Highs on Tue wl run about 10 degrees blo normal with ongoing cold advection. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... A very cold upper trough will propagate towards the area from Quebec Tuesday night and will induce weak cyclogenesis in the Gulf of Maine as another weak surface low in Quebec fills. There`s very little moisture with this system and it will be moving across the area rapidly. The developing system could drop a quick dusting to an inch across the area before it deepens and picks up more moisture east of Maine. With light winds and variable cloud cover, lows will be challenging for Tuesday night. Will lean towards enough clearing to produce some subzero readings in Aroostook County and single digits to low teens elsewhere. The cold upper trough will slowly cross on Wednesday and generate some very steep low level lapse rates. Expect scattered snow showers to develop by midday and a few could be fairly heavy. The deep mixing layer to at least H800 could also produce gusty winds reaching up to 30 mph in the afternoon. Highs will generally be in the low to mid 20s. Another tough radiational cooling forecast follows Wednesday night. Unusually cold air will be in place with subzero temps north and low single digits elsewhere. With a fairly steady light wind, any radiation inversion will be very shallow and potentially short- lived. Nonetheless, a few hours of decoupling in northern valleys could result in some minus 20F readings. Thursday will feature highs some 15 degrees below normal as the cold air mass will be fully in place. There`s just enough H850 moisture for fair wx cu in the north by midday. Can`t rule out a flurry, but will not include pops at this point. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... The cold air mass remains in place into Sunday. For Thursday night, chances are good for another night of good radiational cooling. Winds will be lighter than the previous night. Fair weather continues under high pressure for Friday, but with southwest winds and warm air advection, highs should be some 7 to 8 degrees warmer than the previous day. On Friday night into Saturday morning, a weakening cold front will cross. Prefer the ECMWF and GEMs over the operational GFS for this feature. It will by a dry front, but did impact the low temp forecast Friday night with less radiational cooling. Although, there`s good cold air advection behind the front, surface temps will be warmer on Saturday as temperatures rise above freezing at Bangor and along the coast. High pressure crests over the area Saturday night and have again gone for subzero temps in the north Saturday night. Clouds will increase on Sunday ahead of a frontal system. A lot of uncertainties remain regarding this system. The first question involves the expected southerly marine flow and whether widespread low clouds will develop over the area Sunday morning. The next question involves the extent and speed of the warming aloft and at the surface. In general, the system will be a warm occlusion in the southern stream overrunning the cold air mass that has been in place all week. Have taken a compromise between the warmer GFS and cooler ECMWF. The result brings mixed precipitation later Sunday into Sunday night. Can`t rule out a potential advisory in the north, but temperatures will rise all night and all precip should be in the form of rain by Monday morning. Monday is shaping up to the warmest day since early February. The duration of the expected warming does not look long enough for hydro issues as subfreezing temps return Monday night. However, the air mass arriving next week is not nearly as cold as this week. && .AVIATION /04Z TUESDAY THROUGH SATURDAY/... NEAR TERM: IFR conditions this afternoon, improving to MVFR around 20z at BGR and BHB. Northern terminals becoming MVFR after 00z tonight. Improvement to VFR later tonight into Tue morning. SHORT TERM: VFR is expected to be the predominant condition from Tuesday night into Saturday with the exception of a brief period of IFR vis in snow Tuesday night. Scattered snow showers with tempo IFR vis are possible Wednesday afternoon...mostly north and east of BGR and BHB. && .MARINE... NEAR TERM: SCA conditions expected thru Tue morning with wind gusts aoa 25kts. Expect winds to dip blo for about 4-6 hrs this evng but increase after 02z. Seas wl rmn above 5ft thru the day on Tue. SHORT TERM: Small Craft Advisory conditions are possible Wednesday into Wednesday night, Thursday night, and Friday into Friday night. Winds reaching gale strength has to be considered Sunday night. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...Small Craft Advisory until 1 PM EST Tuesday for ANZ050>052. && $$ Near Term...Hewitt
Area Forecast Discussion
National Weather Service Jackson MS
855 PM CST Mon Mar 4 2019 .UPDATE... Updated for evening discussion and aviation discussion. && .DISCUSSION... Precipitation will end soon over the Pine Belt region as the weak upper wave pushes quickly east. Have trended down pcpn chances in the evening forecast, and current trends suggest there shouldn`t be any additional concern for potential travel issues. Otherwise, freeze warning remains in effect with strong cold advection continuing. Temperature at JAN has fallen below freezing as of early evening, the first time since the end of January, so a long impactful freeze is expected with temperatures likely not rising above freezing until mid/late tomorrow morning. /EC/ Prior discussion below: Have updated the near term forecast again to increase POPs with precip coverage expanding and now a few CGs being noted by the lightning network along the Hwy 98 corridor. Continuing to get reports of sleet and will keep that going for the next few hours. Sfc wet bulb freezing line is encroaching upon the precip shield over sw MS and will need to monitor southward movement of this line closely for potential bridge impacts along the Hwy 84 corridor, but thus far it still looks impacts will be minimal. This is a fast-moving wave so expect precip to end quickly before midnight over the Pine Belt region. /EC/ Prior discussion below: Given recent reports of sleet in the Alexandria, LA to Woodville, MS area, have added sleet into the late afternoon/evening forecast, but still expect minimal impacts at most. Latest HRRR guidance indicates a significant mid level warm nose that should melt most of introduced ice into that layer, but the sub cloud cold layer forecast ~ -6 C would support refreeze of liquid into sleet. With all this said, sfc temps are expected to remain just above freezing in the precip area and the only concern for impacts would be with a heavier sleet burst that could still accumulate. At this time, expecting any accumulating precip to remain south of the I-20 corridor. /EC/ Prior discussion below: Tonight and Tuesday: Continued much colder than normal and mostly dry for our CWA through the period. The exception to the dry weather will be across the south later this afternoon and into the early evening as a weak disturbance aloft moves across the area and squeezes out some light precipitation. CAA has held temperatures today much cold than normal. A few spots in our northwest were still below freezing at 1 PM. Mid afternoon surface analysis had a >1030mb high centered over the Central Plains. This surface high will draw a little closer to our CWA tonight and Tuesday. This will allow temperatures to drop below freezing again by 9PM across the northwest half of our CWA and the remainder of our CWA shortly after midnight. Tuesday morning lows are expected to range from lower 20s north to the upper 20s southeast. Due to an early growing season, hard freeze warning criteria will be met at most locations and a Freeze Warning remains in effect tonight into Tuesday morning. Record lows for the date Tuesday are a couple degrees colder than forecast lows. There will still be a cold northwest to north wind Tuesday but skies will be mostly sunny. This insolation should allow temperatures to warm into the mid to upper 40s Tuesday afternoon. Normal afternoon highs run from the lower 60s north to the upper 60s southeast. /22/ Wednesday through the weekend: Wednesday morning will be the coldest part of this week as the surface high pressure shifts directly overhead. Low temps will once again fall into the 20s areawide. A Hard Freeze Warning will be needed through part of the morning. Once the sun comes up, temps will rise quickly under clear skies. As the high shifts east, southerly surface flow moves in and warm, moist air begins to filter into the region again. Temps will rebound back to normal values by Thursday. On Friday, a warm front will lift north through the area and collide over the Mid-South with an upper shortwave trough. This collision will allow some showers to form and affect the northern portions of the CWA. Temps will even rise into the 70s in the southern parts of the area. Going into Saturday, a deepening trough moves into the central U.S. The global models still differ in the strength of this system as the GFS has a cutoff low forming while the ECMWF has an open wave. Both models still show a strong cold front pushing through the CWA though in the Saturday night into Sunday timeframe. The severe parameters are looking pretty good at this point with plenty of instability and lots of shear. At this point though, we`re not putting any severe threat into the HWO just yet. We`ll wait and see if the global models continue to show this strong system and come into better agreement with the evolution of this system. An outlook may be needed in the coming days. /10/ && .AVIATION... 18Z TAF discussion: VFR conditions and NNW surface winds ~ 10kt will prevail through the forecast period. Sfc wind will be gusty late Tues morning into afternoon during time of greater boundary layer mixing. /EC/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 25 43 24 53 / 5 0 0 0 Meridian 26 45 24 54 / 7 0 0 0 Vicksburg 26 44 25 50 / 4 0 0 0 Hattiesburg 28 48 26 57 / 30 0 0 0 Natchez 26 44 25 53 / 5 0 0 0 Greenville 25 41 24 45 / 3 0 0 0 Greenwood 24 40 23 48 / 4 0 0 0 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...Freeze Warning until 10 AM CST Tuesday for MSZ018-019-025>066- 072>074. LA...Freeze Warning until 10 AM CST Tuesday for LAZ007>009-015-016- 023>026. AR...Freeze Warning until 10 AM CST Tuesday for ARZ074-075. && $$
Area Forecast Discussion...UPDATED
National Weather Service Jacksonville FL
951 PM EST Mon Mar 4 2019 .UPDATE... Weak cool advection pattern will continue tonight as strong high pressure moves to the central U.S. A shortwave trough in the srn Plains will move quickly to the southeast states late tonight and Tuesday morning, accompanied by increased moisture field and strengthened lift. Models have a decent handle on the current light precip over srn LA to southwest AL, though the NAM seems overly aggressive with the precip compared to the GFS and HRRR overnight hours into the morning. The timing of the precip entering the area is after about 3 am and continuing into the mid to late morning hours, then pushing east of the area. Not much change to the elevated rain chances over the area during this time period with chances ranging from about 40-50 percent over southeast GA to 10-20 percent across the srn most zones. Chance of precip is a little higher over ern parts of northeast FL in the early morning hours. Rainfall amounts up to 0.20 inches are expected. Lows tonight will be in the 40s to lower 50s, with temps being held back by a blanket of clouds coming in from the west after 1-2 am. Colder Tuesday with highs in the 50s to lower 60s. Cold advection and much drier air will filter in Tuesday night into Wed morning with a possible light freeze. Given MOS guidance, the light freeze may extend a little further south over north FL. && .AVIATION... VFR through late tonight. A disturbance will move across the region bringing increased clouds and a chance of rain after 08z and continue through about 15z-16z before moving offshore. Drier conditions expected thereafter. Some MVFR cigs are possible but latest guidance not too confident on low cigs below 2000-3000 ft. Not expected any vsby restriction in the rain at this time as it moves through early Tuesday. Light winds tonight become west to northwest near 8-12 kt and gusty to near 20 kt by late Tuesday morning and afternoon. && .MARINE... Current forecast on track with northwesterly winds of around 10-15 kt and seas up to 2-4 ft. Northerly winds are expected to pick up on Tuesday and advisory conditions will be possible late Tuesday evening. && .PRELIMINARY POINT TEMPS/POPS... AMG 40 56 31 53 / 50 30 0 0 SSI 48 58 36 54 / 50 50 0 0 JAX 45 62 36 57 / 40 60 0 0 SGJ 49 62 40 57 / 20 60 0 0 GNV 46 62 36 59 / 30 50 0 0 OCF 49 64 36 60 / 10 40 0 0 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...Freeze Watch from late Tuesday night through Wednesday morning for Baker-Columbia-Hamilton-Inland Nassau-Suwannee. GA...Freeze Watch from late Tuesday night through Wednesday morning for Appling-Atkinson-Bacon-Brantley-Charlton-Clinch-Coffee- Echols-Inland Camden-Inland Glynn-Jeff Davis-Pierce-Ware- Wayne. AM...None. && $$ Shashy/McGinnis