Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/04/20

Area Forecast Discussion
National Weather Service Buffalo NY
929 PM EST Tue Mar 3 2020 .SYNOPSIS... Rain showers will exit the area from west to east this evening. A few rounds of light rain and snow showers will then continue later tonight through Wednesday with some minor accumulations across the Tug Hill Plateau. High pressure will bring dry weather Thursday before another area of low pressure brings some snow to the area Friday. && .NEAR TERM /THROUGH WEDNESDAY/... Low pressure will continue to move down the Saint Lawrence Valley tonight, with a trailing cold front now moving well east of the area into eastern NY. The steady rain will exit Lewis County by late evening, leaving a break in many areas. Another small area of light showers has moved into portions of Western NY in response to strong DPVA just ahead of a mid level vorticity maxima. A few more areas of light showers will continue overnight in response to the passage of the mid level trough, and also as marginal lake instability and upslope flow develop on strengthening WSW flow. The leftover rain showers will transition over to wet snow showers overnight, first across higher terrain and last in the lower elevations. West to southwest flow and lingering moisture combined with cooling temperatures aloft will result in orographically enhanced snow showers. Could be some minor accumulations for the higher terrain east of Lake Erie, with the best chance for a 1-3 inch accumulation over the Tug Hill. It will breezy for a period behind the exiting surface low, especially closer to Lake Ontario with a several hour period where winds could gust to 35 to 40 mph. Most overnight lows temperatures will fall back into the 30s, but into the 20s across the higher terrain. An upper level trough will pass across the Great Lakes into New England on Wednesday. The upper level regime will promote weak cold air advection into the region along with chances for rain and snow showers. A weak wave will pass through PA from midday through mid afternoon, and this may spread a brief period of wet snow mixed with rain through the Southern Tier. Many of the high-res guidance such as the WRF and HRRR suggest a narrow, more convective line of rain/snow showers also developing for areas south of Lake Ontario. High temperatures on Wednesday should reach the mid 30s to lower 40s. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... An upslope westerly flow and lingering low level moisture will combine to generate some scattered light snow showers east of the lakes Wednesday evening...with these then fading out from west to east during the second half of Wednesday night and early Thursday as high pressure and much drier air builds across our region. The axis of the high will then slowly drift into eastern New York Thursday afternoon...while continuing to provide our region with fair dry weather and at least some partial sunshine through the rest of Thursday. With respect to temperatures...overnight lows Wednesday night will be in the mid to upper 20s...with highs on Thursday then ranging from 35 to 40 east of Lake Ontario to the lower to mid 40s elsewhere. Another low pressure system and its parent sharp mid level trough will then track from the Michigan Straits to Lake Ontario Thursday night...while slowly pivoting its trailing cold front across areas south of Lake Ontario. After a mainly dry first half of the night...this system will spread increasing probabilities for some light snow across our region from west to east overnight...which may be mixed with some rain initially given marginal temperature profiles for rain vs snow. Total nighttime snow accumulations from this should be light...ranging from only a few tenths of an inch in most locations to a half inch to an inch across the higher terrain east of Lake Erie. Otherwise...lows will range from the 25-30 range east of Lake Ontario to the lower 30s elsewhere. As the mid level trough digs further southeastward on will continue to spur secondary surface cyclogenesis well offshore of the mid-Atlantic coastline...with the initial surface low and cold front gradually devolving into a fairly pronounced inverted trough across central and eastern New York. The large-scale deep cyclonic flow and plentiful moisture attendant to these features will help to generate fairly widespread precipitation across our region...with the prevailing northerly flow also helping to promote some modest orographic and lake enhancement south of Lake Ontario. As for ptype...boundary layer temperatures will remain marginal for rain vs snow through early to mid afternoon...which will promote a continued rain/snow mix through that time before steady cooling of the column drives a changeover to predominantly snow by the end of the day. Given expected temperatures...the generally light to modest nature of the precip...and strong early March diurnal influences... expect any snowfall accumulations during Friday to be relatively minor and elevation-dependent in nature...with these ranging from an inch or less across the lower elevations to an inch or two across the higher terrain of the Southern Tier and Bristol Hills. As we move into Friday evening scattered to numerous snow showers will still be ongoing across our region...with the greatest concentration of these again found south of the lakes due to lake and orographic enhancement. As we progress through the night though...high pressure and much drier air building in from the north will result in these becoming much more widely scattered in nature. Expect additional accumulations from these to be on the order of an inch or less...with low level cold advection otherwise helping drive low temperatures back down to 10-15 across the North Country...and to the upper teens and lower 20s south of Lake Ontario. && .LONG TERM /SATURDAY THROUGH TUESDAY/... Expect dry conditions as high pressure will dominate the forecast through the weekend into the start of the work week. At first, the area will be influenced by northerly flow Saturday morning, producing lake effect snows south of the lakes. These snows will diminish by midday Saturday as the wind shifts to westerly due high pressure building into the eastern Great Lakes. The surface high pressure will then slowly push into the mid Atlantic states and eventually off the east coast Sunday through Monday, putting our area in the outer edges of the high. This being said, the region will be under general southwesterly flow which will allow for temperatures to rebound back into the upper 40s and low 50s Sunday and Monday. The next chance for showers will come late afternoon/early evening Monday. An upper level trough and associated surface low will track northeast from the Midwest Monday afternoon reaching the eastern Great Lakes Monday evening. As the low continues to track northeast Tuesday, the area will likely see general rain showers throughout the day. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... Steady rain associated with a surface low and cold front is exiting the eastern Lake Ontario region this evening. This has been replaced by an area of light showers in Western NY in response to the mid level trough crossing the eastern Great Lakes. Conditions have mostly improved to MVFR and VFR behind the cold front, with areas of IFR CIGS and VSBY in BR relegated to areas northeast of the lakes as moisture crosses the cold lake waters. The period of IFR northeast of the lakes including KBUF and KART will be brief. Drier and cooler air moving in overnight will allow for improving conditions. A few more brief periods of rain/snow showers will continue overnight and continue through Wednesday. A few of these showers will briefly drop VSBY to MVFR and IFR, with mainly VFR between showers. A mix of MVFR and VFR CIGS will continue, with the lowest CIGS in showers and across higher terrain. Outlook... Wednesday night...MVFR/VFR with scattered rain/snow showers. Thursday...Mainly VFR with scattered rain and snow. Friday...MVFR/VFR with scattered rain and snow showers. Saturday...MVFR/VFR with scattered snow showers. Sunday...Mainly VFR. && .MARINE... Low pressure will track across the region through this evening. On the back side of the low, west-southwest winds will increase into tonight. There will be a period of small craft advisory conditions on both Lake Erie and Lake Ontario tonight and Wednesday. Winds will become west to northwest Wednesday night behind a passing trough, maintaining small craft conditions on Lake Ontario into Thursday morning. Winds will become southerly and decrease later Thursday as a ridge moves across the region. Winds will sharply become northwest then northerly and increase late Friday and Friday night as a cold front moves across the lake, with another period of small craft advisory conditions anticipated. && .HYDROLOGY... An area of low pressure moving across the area will bring about a quarter to a third of an inch of rainfall into tonight. Some minor snow melt will occur into this evening before colder temperatures return. While the rainfall and snowmelt into tonight is not expected to causing widespread flooding concerns there will be rises on area waterways. The lastest river forecast has several Buffalo Basin creeks reaching action tonight through Wednesday. The Rapids forecast point on the Tonawanda Creek along with the Lancaster forecast point on Cayuga Creek get within a half foot of flood stage during this time and will be closely monitored. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...None. MARINE...Small Craft Advisory until 6 PM EST Wednesday for LEZ040-041. Small Craft Advisory until 1 PM EST Wednesday for LEZ020. Small Craft Advisory until 11 AM EST Thursday for LOZ043-044. Small Craft Advisory until 9 PM EST Wednesday for LOZ042. Small Craft Advisory until 9 AM EST Thursday for LOZ045. && $$ SYNOPSIS...Hitchcock/TMA NEAR TERM...Hitchcock/TMA SHORT TERM...JJR LONG TERM...EAJ AVIATION...Hitchcock MARINE...TMA HYDROLOGY...TMA
Area Forecast Discussion
National Weather Service Des Moines IA
812 PM CST Tue Mar 3 2020 ...Updated for Near Term Weather Trends... .UPDATE... Issued at 812 PM CST Tue Mar 3 2020 Trends this evening have pointed to the wintry precipitation being a bit farther south than previously thought by about a county or two. This shift can be seen in the arriving 00z NAM as well as recent runs of the HRRR and RAP. There is also some disparity in the amount of QPF and resulting snow. Generally, guidance is pointing towards around an inch or so of snow accumulations. However, the NAM and the 1z NBM v3.2 shows a narrow strip of higher totals from around Emmetsburg to Waverly. While the BUFKIT NAM data has not arrived yet, the NAM has had a very cold boundary layer this winter. Therefore, it is possible that it has a colder than reality surface temperature now and in the near future allowing for its higher snow totals. Further, Iowa DOT road temperatures are still above freezing in the low 40s across northern Iowa early this evening. If there were to be a narrow band of higher snowfall, it would likely be east of I-35 where the precipitation will fall with temperatures and road temperatures that would support more accumulation. Will continue to monitor environment and make adjustments as needed through the evening and overnight. && .SHORT TERM.../Tonight through Wednesday/ Issued at 312 PM CST Tue Mar 3 2020 Confidence: Medium Tonight and High Wednesday Main concern will be impacts from system tonight. Fast moving and compact PV anomaly dropping southeast into Iowa overnight. This will induce a weak surface low and associated H850 feature which are forecast to track across central Iowa, with the Euro placing the sfc low a bit farther south into southern Iowa. The low will track along a cool front dropping south as well. Most of the 12z synoptic models have backed off on qpf amounts with the hires models continuing to suggest a band of higher qpf just north of the low and mainly over northern Iowa. The better forcing arrives over our northwest forecast area around 03z and quickly tracks east and generally existing the east between 09-12z. Currently temperatures are in the lower to mid 40s over the north with mid 50s in the south. Road temperatures are in the mid 60s over much of the region this afternoon. Farther north, daytime temperatures remain in the mid 30s as far north as southern North Dakota. Tonight the area will first need to overcome the drier airmass and also today`s warmth in the lower layers/roads prior to any real impacts tonight. With the potential for up to .20 inches of qpf, even with a changeover across the north, snowfall amounts continue to lean toward lighter amounts of around 1 inch with locally slightly higher totals. Generally it appears to be a battle between the arrival of the surface cooler air and the precipitation crossing the area though temperatures aloft will be cool enough to start off as snow. Tonight`s lows will drop to the mid to upper 20s north while the south drops into the lower to mid 30s. The system will quickly depart Wednesday morning with a return of some sunshine as well as milder temperatures again over the south during the afternoon. High pressure will quickly slide east in the afternoon with a return of southwest flow by late day. .LONG TERM.../Wednesday night through Tuesday/ Issued at 312 PM CST Tue Mar 3 2020 Confidence: Medium to High Other than wind, the bulk of the forecast will be quiet for the next few days. Another storm will track along the US Canadian border late Wendesday night into Thursday with a trailing front and stronger mixing moving across our area. There remains a weak signal for some light precipitation over northern Iowa or southern Minnesota during from Thursday morning through Friday morning but confidence is currently low regarding occurrence. Winds Thursday afternoon will again be brisk with models suggesting that gusts may reach 40 to 45 mph during the late morning and afternoon hours. Will need to monitor for potential headlines. As well, colder temperatures should filter across the region by afternoon; especially north where highs are more likely to be near the 40 degree mark while the south will still see some lower to mid 50s. The drier airmass, stronger winds and mild temperatures over the southwest Thursday could result in an elevated grass fire situation, but will need to evaluate moving forward. The remainder of the extended will see a rapid warm up over the weekend with H850 temperatures reaching 8C by 00z Sunday and as warm as 9 to 10C by 00z Monday. This should propel highs into the 60s by afternoon. Both the GFS and Euro are in decent agreement for Monday into Tuesday with a well developed trough tracking east across the region late Sunday night/Monday followed by high pressure on Tuesday. Showers are likely into Monday then clearing later in the day. Highs will cool Monday into Tuesday back into the 50s then 40s. && .AVIATION.../For the 00Z TAFS through 00Z Wednesday evening/ Issued at 542 PM CST Tue Mar 3 2020 Winds will decrease this afternoon as clouds spread over the area with a quick shot of wintry precipitation expected overnight, mainly over the northern half of Iowa. This wintry precipitation will arrive later this evening bringing MVFR and perhaps IFR at times to FOD/MCW/ALO. Farther south, there could be a brief shower at DSM. Conditions will have improved back into VFR by daybreak Wednesday with light winds from the northwest becoming from the southwest later in the day. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Ansorge SHORT TERM...REV LONG TERM...REV AVIATION...Ansorge
Area Forecast Discussion
National Weather Service Quad Cities IA IL
906 PM CST Tue Mar 3 2020 .UPDATE... Issued at 855 PM CST Tue Mar 3 2020 A fast moving shortwave trough and associated low-level frontogenesis, strongest near 850mb, will lead to light rain and snow developing in north-central Iowa over the next few hours. The precipitation is expected to increase in coverage as it pushes east into eastern Iowa and northwest Illinois near or after midnight. Most locations will only receive light rain and possibly some mixed in snowflakes with no accumulation. However, for areas north of highway 30 a changeover to all snow is likely, especially along the highway 20 corridor. In this narrow zone, which will probably be about a tier of counties wide, snow accumulations of a dusting to around 1 inch are possible. Can`t completely dismiss the potential for amounts near 2 inches in a very narrow band - but only if heavier rates develop as indicated by some recent hi-res models (3km NAM/NSSL/NMM). Confidence is low on totals much above an inch, but it`s worth a mention that localized higher amounts are possible. Main story is to be prepared for stretches of slushy accumulation on pavement where the steadiest snow develops. Otherwise, pavement will probably just be wet where the snow is lighter. && .SYNOPSIS... Issued at 248 PM CST Tue Mar 3 2020 We were enjoying some gorgeous early March weather across the area this afternoon with weak high pressure ridging passing overhead. Low- level mixing resulted in windy conditions, with some gusts even approaching advisory criteria briefly. Temperatures as of 2 PM ranged from 41 in Dubuque to 55 in Keokuk, which was around 5 to 10 degrees above where we should be for this time of year. Off to the northwest, water vapor imagery showed a shortwave over eastern Montana into the western Dakotas, which was producing a mix of rain and snow across the region. This shortwave will be the primary driver of our weather for the short term period. && .SHORT TERM...(This Evening through Wednesday) ISSUED AT 248 PM CST Tue Mar 3 2020 Key Messages: 1) Rain/snow expected across the area from midnight through mid- morning Wednesday. 2) Snow accumulation will remain below one inch. Discussion: Tonight through mid-morning Wednesday... Quiet evening expected before weather turns active briefly. Aforementioned shortwave is progged to quickly move across the north central Great Plains this afternoon and evening, reaching the area overnight. Guidance has been in good agreement of the shortwave strengthening with its southeastward progression and increasing CVA, with a closed surface low now progged to move over the area. This surface low will increase lift and lead to precipitation development. Forecast soundings are indicative of a mix of rain and snow as we juggle with varying depths of temperatures above and below freezing. As of this package, the best chance of seeing snow remains along and north of Hwy 30 where there is a shallower depth of above freezing temperatures to work with and better lift with the the developing surface low (along with better potential for further cooling from evaporation). Here, snowfall amounts of a few tenths up to one inch will be possible with SLRs progged around 7-10:1. I will make note here that the HRRR as of its 18z run is the most aggressive on QPF (likely due to it trying to introduce convective elements) and further south than other CAMs, which is the way it has been trending over the past few runs. Running model certainty tools show that its fairly high and an outlier, but I will pass along this concern to the evening shift. Further south, a mix of rain and snow to all rain is expected through Wednesday morning. Precipitation should come to an end around 6-8 AM. Late Wednesday Morning through Wednesday Night... Skies will clear out in time for the afternoon as another ripple of high pressure ridging build across the area. Temperatures will not be as warm as today due to a lower level of mixing and lighter surface winds, but will still be above normal for early March. .LONG TERM...(Wednesday Night through Tuesday) ISSUED AT 248 PM CST Tue Mar 3 2020 Key Messages: 1) Above normal temperatures and quiet weather primarily expected through the weekend. 2) Slight chance of rain/snow over northeast Iowa and northern Illinois Thursday, with windy condtions also expected. 3) Increasing confidence of active weather returning early next week. Discussion: Thursday... Cold front is progged to pass across the region Thursday morning, ushering in another area of high pressure and slightly cooler temperatures. In addition, there is a slight chance of rain and snow showers in northeast Iowa and northern Illinois where there is better forcing near a surface low. The main story with this front, however, will be the increase in winds Thursday. Once the front passes, the pressure gradient between the high and departing surface low will steepen, leading to an increase in winds by late morning into the afternoon. Guidance is hinting at winds gusts approaching 40 MPH during the afternoon before subsiding during the boundary layer cutoff by evening. Friday... High pressure will pass over the mid-Mississippi River Valley Friday, keeping quiet weather overhead. Cool northwest winds will limit highs to the mid to upper 40s. Saturday through Daytime Sunday... Another weekend, and another warmup! Increasing warm southerly flow and strengthening mid-level ridging will allow temperatures to soar once again heading into the weekend. Afternoon highs in the mid 50s to low 60s are expected Saturday, with widespread highs in the mid to upper 60s for Sunday. This is approaching normals we see in late April/early May! Sunday Night on... Confidence continues to grow of active weather making a return to begin the work week with an approaching front and increasing moisture over the area. There are still uncertainties on rainfall amounts and placement with this front and subsequent surface low, so expect additional changes to this forecast as we head through the week. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening) ISSUED AT 600 PM CST Tue Mar 3 2020 A quick moving low pressure system will bring a band of rain and snow to the area overnight. Snow is favored at KDBQ with a rain/snow mix at KCID and mostly rain at KMLI. Minor slushy accumulation is possible at KDBQ, especially if it snows moderately for an hour or two. Overall, the impacts will be mainly to visibilities and ceilings with MVFR likely and potentially a brief 1-2 hr period of IFR. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...Uttech SYNOPSIS...Speck SHORT TERM...Speck LONG TERM...Speck AVIATION...Uttech
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
828 PM CST Tue Mar 3 2020 .UPDATE... Things have been slow going thus far on area radars as of 815 pm with only some elevated returns beginning to stream into our western counties from the southwest. Latest mesoanalysis shows little to no CAPE at the present time which is why we aren`t seeing any sustained convection at this time. However, the upper low remains southwest of the area and as the low continues to move east, deeper forcing will arrive which will introduce more instability to the area. The latest run of the HRRR shows some better convection by 06z but the overall trends of the latest runs show somewhat less of a trend of a linear system with more of scattered thunderstorms within an area of rain. Given the shear, some of these could still be strong to severe with possible hail and damaging winds being the main threats. The best chances for severe weather remain in the slight risk closer to the path of the expected surface low. && .PREV DISCUSSION... /ISSUED 528 PM CST Tue Mar 3 2020/ AVIATION... Large scale forcing for ascent should approach the region over the next 12-18 hours and bring periods of showers and storms to the area terminals. This should begin at DRT around 2-3z lasting into the 11z hour and at the I35 sites between 4z and 16z. Some of these storms could be strong at times. In addition to the threat of storms, MVFR/IFR conditions can be expected with both ceilings lowering throughout the night and periods of visibility restrictions within the heavier thunderstorm activity. Conditions should improve to VFR at DRT around 14z and SSF/SAT around 16z with drying conditions. AUS will likely remain MVFR throughout tomorrow, as wrap around moisture lingers there on the backside of the upper low. PREV DISCUSSION... /ISSUED 213 PM CST Tue Mar 3 2020/ SHORT TERM (Tonight through Wednesday Night)... The main forecast issue in the short term is the prospect for severe convection and heavy rainfall. The 12Z regional/global models are in good agreement with the synoptic morphology of moving the shortwave trough now over northwestern Mexico across Texas over the next 36 hours. This trough is fairly high amplitude and slow moving, so we expect a little bit longer than average period of sustained lift. Therefore, high PoPs (especially Wednesday morning) are a given. Despite the synoptic-scale agreement, the mesoscale details differ, especially in regards to convective timing and intensity. There seem to be two camps, with the Texas Tech WRF, HRW ARW, and other typically "Dry Plains Environment" models keeping cellular convection confined to the Rio Grande Plains, and generally only bringing a weak line of storms across the rest of the area. In contrast, the HRRR and HRW NSSL have a more coverage and stronger cellular convection over the Rio Grande Plains, and carry an short- line MCS through the eastern Hill Country and northern half of the I- 35 corridor. This is one of those cases where splitting the difference is not an appropriate solution -- it will either be one morphology or the other. Given the release of CAPE earlier this morning over northern Mexico, it seems a phase-shift to the east would be a preferred outcome for tonight. This would also line up with the diurnal strengthening of the LLJ. The result should be close to the TTech WRF and ARW solutions of lesser activity, both in coverage and intensity. That said, there could still be isolated hail and wind damage reports with some of the stronger storms, especially on the Rio Grande Plains, but the I-35 corridor, including Austin and San Antonio, should see sub-severe storms. Rainfall amounts through Wednesday night will vary widely, from 1/10 to 1/4 inch in the southeast coastal plains, to 1-2 inches in the Edwards Plateau and Hill Country. One or two spots in Llano, Burnet, or Gillespie counties may see up to four inches of rain. While there main be some minor flooding of the low water crossings and other typical spots, we do not foresee significant flooding. The moderate to heavy rain should end by noon Wednesday, but moisture wrapping around the low will maintain scattered showers along and north I-10 until sunset Wednesday. FIRE WEATHER... Strong gusty winds and low humidity in the southwestern corner of our CWA, including Eagle Pass, will lead to Near Critical Fire Weather conditions on Wednesday afternoon. Severity will be dependent on rainfall amounts in the area. This area will need to be watched for further actions. LONG TERM (Thursday through Tuesday)... With the system moving out of the area to the northeast, ridging builds in behind it. Thursday, cooler and drier air will take a few degrees off of the high temperatures bringing back down to near normal of upper 60s and low 70s. We maintain a dry forecast through the weekend with winds switching back out of the southeast on Saturday. This will kick off a warming trend into the beginning of next week. Next chances for rain are Sunday through Monday with abundant moisture in place as multiple disturbances in the southwest flow. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 61 66 47 68 46 / 90 80 10 0 0 Austin Bergstrom Intl Airport 61 68 46 69 45 / 90 80 10 0 0 New Braunfels Muni Airport 62 71 46 69 45 / 80 60 - 0 0 Burnet Muni Airport 55 59 43 67 43 / 90 90 10 0 0 Del Rio Intl Airport 56 67 45 73 46 / 70 20 0 0 0 Georgetown Muni Airport 58 62 45 68 44 / 90 90 10 0 0 Hondo Muni Airport 60 71 44 73 43 / 60 40 0 0 0 San Marcos Muni Airport 62 70 46 69 45 / 80 70 10 0 0 La Grange - Fayette Regional 64 75 48 68 45 / 70 80 10 0 0 San Antonio Intl Airport 63 75 47 71 47 / 70 50 - 0 0 Stinson Muni Airport 65 76 48 71 47 / 60 40 - 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term/Aviation...Hampshire Long-Term...BMW
Area Forecast Discussion
National Weather Service Grand Forks ND
954 PM CST Tue Mar 3 2020 .UPDATE... Issued at 951 PM CST Tue Mar 3 2020 Area of showers moving southeast thru central ND associated with 500 mb vort which is moving right over Bismarck. Few lightning strikes even west of Mandan with this feature. Second night in a row for that area. For eastern ND and NW/WC MN skies mainly clear, though there are a few cloud patches in the nrn RRV and far NW MN from clouds trying to move SE from Manitoba. Also some mid level clouds brushing the far west/southwest fcst area with that wave to the west. Will maintain eastern edge of low pops for far SW fcst area, but most of the precip will miss us to the southwest. Temps holding up pretty well within fcst range, exception being Langdon airport dropping to 10F, but NDAWN at 16 there. So overall left temp fcst as is. HRRR backing of a tad on fog development but still has some and NBM has some as well but not as much as earlier runs. Will still monitor. Best chc seems to be just east of the Red in the eastern RRV from Crookston to Moorhead. UPDATE Issued at 648 PM CST Tue Mar 3 2020 High pressure will move over the area tonight. Band of clouds to our west will slowly spread east and overnight move into the DVL basin as the high moves east. Another batch of clouds is near Lake Manitoba and the La Portage Prairie region and it is sliding slowly southeast. Unsure what to make of this cloud area so will need to monitor. Main impacts overnight will be does fog form in the area as the high moves through, with guidance still targeting the mid Red River valley. Short range guidance insists on it in various degrees of coverage. Will monitor, but confidence to throw in fog at this point remains low. && .SHORT TERM...(This evening through Wednesday night) Issued at 318 PM CST Tue Mar 3 2020 Weather and impacts for the short term continue to be driven by clipper series. Weak surface high pressure will settle in over the forecast area this evening and for the overnight. As the remnants of the stratus deck erode or clear in this evening the potential for fog development is being advertised in much of the guidance for early morning time frame on both sides of the north and central valley and across the Devils Lake basin. Similar conditions to last week when guidance suggested fog and none formed 3 out of 4 nights. So will leave out of the forecast for now. In SE ND some light snow is possible as an area of precip moves out of central ND with another clipper. South winds develop quickly Wednesday morning in response to WAA ahead of the next clipper. WAA wednesday afternoon and evening could bring some light snow to NW MN. In the warm sector of the clipper Wednesday afternoon and evening there is potential for some shower activity, rain or snow possibly a mix, depending on the strength of the warm nose and amount of saturation in the mid levels. .LONG TERM...(Thursday through Tuesday) Issued at 318 PM CST Tue Mar 3 2020 12Z Thu - 00Z Sat Water vapor loop indicated a short wave/jet streak approaching the BC coast. Short wave will be moving out of the forecast area by Thu morning however a secondary short wave will pass through Thu. Deformation zones over northern Canada will shift east. GEFS indicated most likely area for precip over northwest MN Thu. Cold front will move south across the forecast area Thu. Windy conditions are expected with good surface pressure gradient and respectable pressure rises for Thu. Adiabatic low level lapse rates are expected by late morning and into the afternoon Thu. Adiabatic lapse rate layer is rather shallow up to around 3k ft. About 40 knot wind potential to mix down. However cold advection is not that strong Thu and pressure grad does shift east during the afternoon. Travel impacts will be possible for Thu with high profile vehicles. Blowing snow is expected to be minimal with relatively old snowpack and recent mild temps. Upper level ridge amplifies in the west and shifts over the Northern Plains Fri. Sat - Tue Upper level ridge continues to shift east this period with warm air moving into the area on Sat. Short wave to move across central Canada and will send a shot of cooler air out of Canada on Sun. Cooler air will be possible for Sun and Mon with some moderation by Tue. Ensemble guidance indicates the potential for up to 4 inches snow during a prolonged Mon/Tue period over parts of northwest MN with less across the valley and eastern ND. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 533 PM CST Tue Mar 3 2020 High pressure will move southeast and be over the Red River valley 06z-09z period. Short range models picking up on light winds and enough low level moisture to generate fog in the mid Red River valley. Highly uncertain yet of this and for now will mention possibility here but not yet include in GFK/FAR/TVF TAFs for the overnight. Clouds from the west will move east late tonight into Wed AM as warm advection kicks in. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...Riddle SHORT TERM...JK LONG TERM...JH AVIATION...Riddle
National Weather Service Hastings NE
627 PM CST Tue Mar 3 2020 ...Aviation Update... .SHORT TERM...(This evening through Wednesday) Issued at 208 PM CST Tue Mar 3 2020 Aloft: Low-amplitude W-WNW flow was over the NEB/KS per aircraft wind data and RAP tropopause animations. A wk shrtwv trof was over MT and sliding SE. This trof will rapidly cross SD/NEB this eve followed by slightly anticyclonic WNW flow into tomorrow. Surface: Wk 1014 mb high pres was along the KS/OK stateline. This high will be squeezed by a wk low that will form near YKN and then move into IL tonight. A developing cool front associated with this low will cross the CWA this eve. Anticyclogenesis will then occur over the Cntrl Plns tomorrow with return flow developing in tandem with low pres moving acrs Srn Canada. Rest of this afternoon: Mostly sunny...warm and breezy. Highs in the low-mid 60s will occur 4-5 PM. Tonight: Mostly clear. There will be a few clds around early that could result in some sprinkles here and there. After 10 PM... clear. Lows within a cpl degs of 30F. Wed: Sunny. Becoming breezy after 18Z...espcly N and W of HSI with G25-30 kt will be common. .LONG TERM...(Wednesday night through Tuesday) Issued at 208 PM CST Tue Mar 3 2020 Pattern: No change in the main theme since mid Nov. Lots of W-E flow off the Pac. Low amplitude will occasionally increase to moderate amplitude. Aloft: The longwaves will amplify a bit Thu-Sat...and then deamplify heading into early next week. The flow over NEB/KS will be NW Thu...behind a deepening shrtwv trof moving into the Ern USA. The moderate-amplitude ridge over the Wrn USA will cont E and crest over the Plns Fri eve. Behind it...WSW flow will prevail Sat-Sun. A shrtwv trof that originates off CA will move thru the Desert SW and cross the Cntrl/Srn Plns Mon AM. Zonal flow will occur in its wake Tue. Surface: 1030 mb high pres will emerge onto the Plns Thu and cont to strengthen as it gradually shifts into the MS Vly Fri and into the SE USA this wknd. As the high moves away...breezy/very warm return flow will remain over NEB/KS until a Pac cool front moves thru Sun night. Nrn Plns high pres will then build in Mon- Tue. Temps: Way warmer than normal with a warming trend thru Sun...then temps return back to near normal Mon-Tue. Sat-Sun cont to trend warmer and we`re now looking at 2 days with widespread low-mid 70s. Precip: Dry until the frontal passage Sun night. Rain appears likely Sun night into Mon. The ptype routine has some snow N and W of the Tri-Cities...but that is based purely on sfc temps and our lows are probably too chilly. Am expecting this to be all rain. Let the NBM thunder probs dictate its inclusion. So there is now a slight chance of thunder Sun eve. Both the GFS and EC have 50F dwpts surging into the SE CWA to meet the front. That should create sufficient/weak instability to support some thunder. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Thursday) Issued at 626 PM CST Tue Mar 3 2020 High confidence in VFR ceiling/visibility through the period with clear skies the vast majority of the time, although these first few hours will feature a fairly solid mid-level cloud deck (ceiling around 10K ft.) along with the possibility of a few brief sprinkles. That leaves winds as the main aviation issue, both at the surface and aloft, as much of tonight will likely feature at least marginal low level wind shear (LLWS). Read on for more wind-specific details... Surface winds: Generally speaking, most of the night and Wednesday morning will feature a westerly to west-northwesterly breeze sustained in the 8-12KT range, although occasional gusts to 20+KT cannot be ruled out (especially these first few hours). A more notable occurs late morning into the afternoon, as direction transitions to southwesterly sustained generally 14-18KT/gusts 19-25KT, before subsiding a bit by late afternoon. LLWS: Have maintained the inherited mention of LLWS overnight, and extended it by 1 hour, now focusing 03-10Z. In, short, winds within roughly the lowest 1K ft. above the surface will increase to around 40KT from the northwest, promoting generally 30-35KT of overall- shear magnitude between the surface and this level. && .FIRE WEATHER... Issued at 208 PM CST Tue Mar 3 2020 Near critical RH/winds this afternoon in some spots. Critical RH/winds are expected Wed afternoon. So a RFW has been posted for Dawson/Gosper/Furnas/Harlan/Phillips counties. Outside of the warning...near critical. Thu will be another day of critical or near-critical RH/wind. Fri and Sat will be windy...but low-lvl moisture should come up just enough to keep RH`s above 30%. && .GID WATCHES/WARNINGS/ADVISORIES... NE...Red Flag Warning from noon to 6 PM CST Wednesday for NEZ060-072- 082-083. KS...Red Flag Warning from noon to 6 PM CST Wednesday for KSZ005. && $$ SHORT TERM...Kelley LONG TERM...Kelley AVIATION...Pfannkuch FIRE WEATHER...Kelley
Area Forecast Discussion
National Weather Service Gray ME
745 PM EST Tue Mar 3 2020 .SYNOPSIS... After record high temperatures in some areas today, low pressure will move in from the southwest tonight bringing a brief period of rain before a cold front moves through Wednesday morning. Mountain areas will see some snow. Wednesday will still be warm but rather windy with temperatures cooling into the end of the week. A brief ridge of high pressure will build into the region Thursday before low pressure develop off the Eastern Seaboard on Friday. This system will pass well east of our region Saturday. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... Update...Warm advection wing of precip moving thru the heart of the forecast area now. I have adjusted PoP to represent trends with the band over the next few hours. Dewpoints are largely above freezing across the this is expected to fall as rain overnight...except for the highest peaks. The next area of precip will move thru late tonight with the S/WV trof itself. Temps aloft will be sharply falling behind it...and precip may briefly change over to snow before ending. Snow showers will continue in the mtns. Previous discussion...High temperatures will continue to fall across portions of the region this afternoon. 12Z guidance in good agreement with the near term portion of the forecast. Low pressure gradually develops as it moves up the Saint Lawrence River Valley tonight. Rain will move into the region this evening from southwest to northeast. The latest HRRR continues to show two batches of precipitation with a second area of rain arriving around and shortly after midnight. Some snow may fall in northern areas with light accumulations. Over the Presidentials, significant accumulations are possible above 2500-3000 feet. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... Skies clear tomorrow morning as low pressure intensifies and exits into the Canadian Maritimes. A westerly gradient will increase as the upper low features shift to the east. Warm temperatures for this time of the year will allow for increased mixing values as well. After coordination with adjacent offices, will issue a wind advisory for Wednesday for all areas with the exception of the Connecticut River Valley. This scenario matches well with our neighbors. Some minor additional accumulations of snow expected in the mountains where upslope conditions will persist. Temperatures will be above normal for this time of the year, despite the cold air pouring into the region. Look for highs well into the 40s over central and southern areas. By Wednesday night, winds will still be gusty but slowly easing slightly. A few upslope snow showers may continue over the high terrain. && .LONG TERM /FRIDAY THROUGH TUESDAY/... The ensemble and deterministic model solutions remain in good agreement on the long wave pattern through the upcoming weekend and the start of next week. Northern stream energy will dominate this period. The question mark remains the degree of interaction between streams in the Friday and Saturday timeframe...impacting the timing and placement of the ocean storm. With the mean jet position remaining`ll be an active period but with above normal temperatures as arctic air remains largely confined to our north. The forecast period begins with weak ridging and quiet weather for late Thursday into Friday. Northern stream disturbance approaches from the Great Lakes Friday while a southern stream disturbance emerges off the southeast CONUS. Eventually this energy congeals into a single offshore system...that could brush coastal sections with a period of light snow or snow showers Friday night - early Saturday as the column cools. The ensemble trend overnight is once again slightly further offshore with this system with light QPF amounts confined to southern and coastal sections. Behind this system...a ridge of high pressure settles across the region during Saturday. A weak frontal boundary may settle south into northern sections Saturday night through Monday with clouds and widely scattered rain or snow high pressure builds by to our south. && .AVIATION /01Z WEDNESDAY THROUGH SUNDAY/... Short Term...VFR conditions early this evening will be lowering to IFR and LIFR in low cloudiness and rain as low pressure approaches from the southwest. Conditions improve Thursday and Thursday night, however winds will be very gusty from the west during this period with some gusts above 45 mph. Long Term... Fri PM- Sat AM...Sct MVFR and lcl IFR psb at coastal TAF sites in -SHSN/-SHRA. && .MARINE... Short Term...Have issued gales for the coastal waters for Wednesday into Wednesday evening. Healthy westerly gradient and cold air advection will allow for gale force winds over the coastal waters. Wind will gradually ease late Wednesday night into Thursday as low pressure continues to exit through eastern Canada. Long Term... Thu...SCA`s likely outside the bays. Fri Night - Sat...SCA likely with Gales psb outside the bays. && .CLIMATE... Record highs for today... Portland, previously 55 degrees set back in 1961. The Jetport reached a high temperature of 61 degrees...breaking the old record. Concord, previously 62 degrees set back in 1874. Concord reached a high temperature of 62 degrees...tying the old record. Augusta, previously 60 degrees set back in 1964. Augusta reached a high temperature of 54 degrees...falling short of the old record. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...Wind Advisory from 6 AM to 6 PM EST Wednesday for MEZ007>009- 012>014-018>028-033. NH...Wind Advisory from 6 AM to 6 PM EST Wednesday for NHZ001-002- 004-006-008>010-012>015. MARINE...Gale Warning from 6 AM Wednesday to midnight EST Wednesday night for ANZ150>154. && $$ NEAR TERM...Legro
Area Forecast Discussion
National Weather Service Houston/Galveston TX
912 PM CST Tue Mar 3 2020 .SHORT TERM [Through Tomorrow]... Overall there is not much change in the forecast but wanted to toss out a few thoughts on the marginal severe weather outlook for tomorrow. Frontal boundary is currently stalled from the Arklatex WSW towards west central Texas this evening. Front should slowly sag south but it will take it`s time doing it since there will be an upper level low moving into central Texas with a positive tilt. As this low moves east from the Big Bend area, there should be increased large scale lift spreading over central Texas through the morning hours. We could see a QLCS type line develop in central Texas and move towards College Station/Crockett area in the late morning hours. Instability is not all that great but any interaction with the frontal boundary could increase shear locally for a mesovortex spin up. Again, this is not a great environment for severe weather just because instability will be marginal. We hate cherry picking one particular deterministic model run, but the last run or two of the HRRR like the 00Z run have also raised an eyebrow with convection forming in the afternoon as a surface low pressure organizes over the area. Boundary layer winds veer to the W during the course of the afternoon and the frontal boundary sags into the Houston area and down towards Wharton. South of the boundary there will be 70+ dewpoints and possibly enough instability for more robust convection. IF and that`s a big IF, a storm can become surface based and track along the frontal boundary then we might get an isolated severe storm. So we will see if this forms but the lion share of models bring a dry slot into the area and we get nothing. So in the end, we are just hedging our bets and do not want to be caught off guard. Overpeck && .PREV DISCUSSION /Issued 551 PM CST Tue Mar 3 2020/... .SHORT TERM [Tonight through Wednesday Night]... Further development of sea fog continues to be a concern in the immediate term, with ample low-level moisture and light onshore winds still present across the bays and the offshore waters. Some inland areas could also see fog development this evening as we saw overnight yesterday. As a result the Marine Dense Fog Advisory has been extended through tomorrow morning, after which drier air behind an advancing surface front and offshore winds should clear the fog threat heading into the weekend. The forecast for the rainfall event tonight and into tomorrow has remained largely on track. Global model guidance continues to indicate the upper low progressing eastward towards the Big Bend region this evening and further into Central TX by tomorrow afternoon. NAM, HRRR, and GFS show PWAT values surging to as high as 1.7" by tomorrow morning, which is well into the upper quartile of the climatological distribution for early March at nearby sounding locations. As a developing surface low pushes northeastward heading into the evening hours, sufficient surface lift along a slowly advancing frontal boundary and favorable divergence aloft in the exit region of an upper-level jet streak will allow for increasing coverage of showers by Wednesday morning. Greatest rainfall totals continue to be focused generally to the north of the I-10 corridor, with GFS and ECMWF in good agreement in showing a swath of higher values across the northern counties of the CWA. Around 1-2" continues to look in store for many locations north of the Houston metro area while totals drop off to around 0-25-0.5" near the coast where dynamics remain less favorable. Rainfall coverage gradually tapers off as the surface low exits the region on Wednesday afternoon and the frontal boundary pushes offshore. SPC has maintained a marginal risk in its convective outlook for portions of the northern half of the CWA. While convective allowing models have indicated the potential for some stronger storms developing to our west by tomorrow morning, the environment that any storms progressing into the western counties will encounter appears to be less favorable for stronger convection due to limited instability. Nonetheless, some isolated thunderstorms remain a possibility with tomorrow`s activity, particularly in the northern counties. Cady .LONG TERM [Thursday Through Tuesday]... Behind tonight and tomorrow`s active weather pattern, expect calm, dry, and seasonable weather conditions to prevail heading into the weekend as upper level ridging and surface high pressure take hold over the central CONUS. Clearer skies, daytime highs in the upper 60s to low 70s, and north to northwest winds will be in store across SE TX through Saturday. Look for a return to onshore winds and increasing moisture as the surface high pushes eastward on Sunday, with rain chances consequently increasing as we head into next week. Our next potential period of active weather comes as a shortwave trough digs into the south central CONUS on Monday. Cady .AVIATION [00Z TAF Issuance]... Not much change in the big picture for this cycle, as VFR gives way to degrading flight conditions through the night, along with increasing chances of showers (and some storms from IAH northward). Look for rain to come to an end at some point at the end of the TAF period, with flight conditions to improve (slowly inland, rapidly on the coast). However, have largely left this out of this forecast cycle due to uncertainty in precise timing. Look for more details in the 06Z TAF on this trend. .MARINE... The onshore flow will persist into tonight and early tomorrow. This will allow for areas of sea fog to continue to possibly develop and become dense at times along the coast/bays and into the nearshore waters. The long fetch that is in place and helping to produce 3 to 5 foot seas should gradually increase as pressures fall off to our west into Wednesday. Have hoisted caution flags for the offshore waters beginning this evening, and it is possible that these flags might need to be stretched closer to the coast and maybe even raised to an advisory later tonight or tomorrow. The Texas storm system and associated cold front will move across our area during the day on Wednesday and will eventually allow winds to shift to the northwest and bring an end to the fog threat. The tightened pressure gradient will eventually bring elevated winds and seas to the area that will likely require caution and/or advisory flags probably beginning Wednesday afternoon or evening and especially on Wednesday night and Thursday. High pressure influencing the area at the end of the week and moving off to the east over the weekend will allow the north to northeast winds at the end of the week to shift to the southeast over the weekend. 42 && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 65 66 47 67 46 / 60 80 40 0 0 Houston (IAH) 67 72 51 66 50 / 70 70 20 0 0 Galveston (GLS) 63 68 54 64 55 / 60 40 20 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...Dense Fog Advisory until 9 AM CST Wednesday for the following zones: Coastal waters from Freeport to Matagorda Ship Channel TX out 20 NM...Coastal waters from High Island to Freeport TX out 20 NM...Galveston Bay. SMALL CRAFT SHOULD EXERCISE CAUTION until 6 AM CST Wednesday for the following zones: Waters from Freeport to Matagorda Ship Channel TX from 20 to 60 NM...Waters from High Island to Freeport TX from 20 to 60 NM. && $$ SHORT TERM...Overpeck LONG TERM...Cady AVIATION...Luchs
Area Forecast Discussion
National Weather Service Jacksonville FL
910 PM EST Tue Mar 3 2020 ...ISOLATED TO SCATTERED SEVERE STORMS POSSIBLE WEDNESDAY MAINLY NORTH OF I-10... .UPDATE... A line of weak showers is moving through parts of southeast GA this evening associated with prefrontal trough. Some stronger forcing associated with a shortwave trough/vort lobe is moving through the FL panhandle, and coupled with more instability is producing scattered showers and a few storms in that area. So with these two areas of forcing, rain chances will increase over the nrn half of the area through later tonight. Given the weak instabilty though will have isolated thunderstorms rest of tonight. Can`t rule out a strong to possibly severe storm toward 12z over inland southeast GA, as subsidence inversion in the mid levels weakens and allows for potential deeper convection. The stronger cells would be most likely near a cold front that stalls over southeast GA Wednesday morning. SPC shows marginal risk for severe for southeast GA through sunrise Wednesday. Latest HRRR guidance shows one or two stronger convective cells moving east- northeast late tonight that end up weakening, likely due to moving further away from higher instability to our west. For the update, will adjust timing of precip a bit. Otherwise, temps and sky cover look good with temps only slowly falling due to increased clouds and light south- southwest winds. Min temps in the mid 60s, possibly upper 60s in some locations. .MARINE... South to southwest winds around 10-15 kt rest of tonight, with seas near 3-5 ft. Winds appear to have decreased a bit since earlier so will remove SCEC headline. Otherwise, forecast is on track. && .PREV DISCUSSION [724 PM EST]... .NEAR TERM [Through Wednesday]... The cold front entering the southeastern states will push southeastward through southeast Georgia during the predawn and early morning hours, accompanied by increasing showers and a few embedded elevated thunderstorms after midnight across southeast Georgia as diffluence aloft strengthens within the active subtropical jet in place over our region. Steepening lapse rates and the arrival of weak shortwave energy from the northern Gulf of Mexico may develop a few strong thunderstorms along or just south of the sinking frontal boundary during the predawn hours, with the potential for a few right- moving supercell thunderstorms developing along the FL/GA border or perhaps as far south as Interstate 10 towards sunrise. Low stratus ceilings will likely advect east-northeastward across north central Florida during the predawn hours, where patches of locally dense fog may also develop. Warm air advection should keep lows in the 60s nearly area-wide overnight. The cutoff cyclone will pivot eastward across Texas on Wednesday, resulting in the frontal boundary slowing its forward progress as it moves across the FL/GA border. Strengthening isentropic lift will likely develop moderate to heavy rainfall for locations north of this stalling boundary, with a few embedded elevated thunderstorms possible throughout the day across southeast Georgia. We have issued a Flash Flood Watch for locations north of a line from Pearson to Waycross to Jesup, where stronger lift should result in widespread heavy rainfall through Wednesday evening. A few of the short-term, high resolution models develop isolated to widely scattered convection along the Interstate 10 corridor around sunrise, suggesting that a few right-moving supercells may progress eastward along an outflow boundary originating from overnight convection over southeast Georgia. Steep lapse rates and strong westerly wind shear within the hail growth zone could result in a few strong to severe thunderstorms, with large hail and downburst winds being the primary threats. This convection could impact the morning commute in northeast Florida, so trends with the short term guidance will be closely monitored overnight. A large temperature gradient will become established over our area on Wednesday, with highs likely staying below 70 for locations near the Altamaha/Ocmulgee Rivers, while warm and breezy conditions boost highs to the mid and upper 80s in north central Florida. .SHORT TERM [Wednesday Night Through Friday Night]... Cyclogenesis is expected along the Upper Texas coast on Wednesday, with the upstream cutoff cyclone opening up into a potent shortwave trough on Thursday as it moves east-northeastward across the southeastern states. The frontal boundary in place along the I-10 corridor may backdoor its way down the northeast Florida coast on Wednesday night, followed by a brief surge of northeasterly winds along the coast for locations north of St. Augustine. There may be a brief lull in heavy rainfall overnight over southeast Georgia before isentropic lift strengthens as the storm system approaches from the west on Thursday morning. Lows Wednesday night will range from the mid 50s near the Altamaha River to the mid and upper 60s for locations south of the frontal boundary in north central Florida and the Suwannee Valley. Heavy rainfall will redevelop over southeast Georgia on Thursday morning as the frontal boundary retreats northward as a warm front Widespread rainfall totals of 3-5 inches with locally higher amounts will be possible in the Flash Flood Watch area. Model guidance otherwise remains in decent agreement on timing and details as low pressure moves east-northeast from the Florida panhandle early on Thursday morning across southeast Georgia during the afternoon hours and off the South Carolina coast by early evening. The warm sector will overtake all of northeast and north central Florida, with the threat for a squall line of strong to severe thunderstorms moving from west to east across these areas during the afternoon and early evening hours. Impressive west southwesterly speed shear continues to be noted in model soundings, with 50-60 knot winds depicted at 850 millibars (around 4,500 feet), steep lapse rates and CAPE values of 1,000-1,500 j/kg in the warm sector. Damaging wind gusts and possibly a few tornadoes will be possible for locations along and south of I-10 through around sunset. Highs on Thursday will range from the lower 60s near the Altamaha River to the mid and upper 80s in north central Florida, while most locations along and south of I-10 reach the 80s. Low pressure will strengthen off the Carolina coast on Thursday night, which will push this storm system`s cold front offshore towards midnight. Convection should move offshore by early evening as well, with northwesterly winds becoming breezy and driving lows down to the mid to upper 40s across southeast Georgia and the northern Suwannee Valley, with 50s elsewhere as cloud cover decreases from northwest to southeast during the overnight and predawn hours on Friday. Stronger cold air advection will lag this storm system somewhat as a potent shortwave trough dives southeastward from the Canadian Prairies across the Great Lakes region on Friday, which will sharpen troughing along the eastern third of the nation by late Friday. A dry air mass, plenty of sunshine and breezy northwesterly winds will allow highs to climb to near early March climatology on Friday, with highs generally reaching the 65-70 range, except lower 70s in north central Florida. Cold air advection then will arrive on Friday evening, driving lows down to the 35-40 degree range inland by sunrise on Saturday and 40-45 at the coast, with wind chills around freezing expected. .LONG TERM [Saturday Through Tuesday]... Deep troughing that resides along the U.S. eastern seaboard on Saturday will progress offshore on Sunday, allowing for zonal flow to develop by late in the weekend and early next week. Strong surface high pressure extending from the Great Lakes region into the Tennessee Valley on Friday night will settle southeastward towards the Carolina coast by Sunday evening. Below climo highs are expected on Saturday as low level flow veers from northerly to northeasterly, and decoupling winds at inland locations on Saturday evening could result in frosty conditions inland by early Sunday morning. Onshore winds will allow inland highs to recover back towards climatology on Sunday, followed by another warming trend early next week. A decaying frontal boundary entering the southeastern states could develop a few showers by late Tuesday afternoon. .AVIATION... [Through 00Z Thursday] VFR cigs expected through the late evening, then increasing chances for showers and potential isolated storms from the west after midnight. Most of the showers will be along and north of I-10 through 12z Wed. Cigs expected to trend to MVFR and then IFR for TAFS late tonight with best chances of IFR for GNV, VQQ, JAX, and SSI by the 09z-13z time frame. LIFR cig possible at GNV but confidence is currently low on this potential. Some gradual improvement in cigs possible by 15z-18z, but could trend back down in the late aftn. However, more persistent low cigs likely around SSI all day. Best chance of showers and storms Wednesday will be north of GNV-JAX line. Some of the storms could be locally strong to severe. Winds will be southwest to south tonight aob 10 kt, then increase again on Wednesday morning. .MARINE... A cold front moving through the southeastern states late this afternoon will cross the Georgia waters on Wednesday morning, with a few strong thunderstorms possible for the waters north of St. Augustine. Small Craft should continue to Exercise Caution offshore through Wednesday evening offshore, where sustained winds of 15-20 knots and seas of 4-6 feet will prevail. The cold front will push over the northeast Florida waters Wednesday night, followed by a brief surge of northeasterly winds through early Thursday. Meanwhile, low pressure developing along the upper Texas coast Wednesday morning will move east-northeastward along the I-10 corridor on Wednesday night and Thursday, with a strong cold front accompanied by strengthening southwesterly winds and strong to severe thunderstorms crossing our local waters on Thursday afternoon and evening. Low pressure will strengthen as it accelerates northeastward off the U.S. eastern seaboard on Friday, with strong northerly winds expected through Saturday. Small Craft Advisory conditions will overspread our local waters Friday afternoon and evening, with conditions possibly improving to Caution levels near shore by Saturday afternoon. Winds will become onshore by Saturday evening with gradually decreasing speeds, allowing seas to gradually subside by late in the weekend. Conditions may improve back to Caution levels offshore by Sunday. .FIRE WEATHER... Breezy south-southwesterly surface and transport winds will continue for locations south of Interstate 10 on Wednesday, while low daytime dispersion values are expected throughout southeast Georgia on Wednesday and Thursday. Rainfall amounts of 3 to 5 inches with locally higher totals will be possible over portions of inland southeast Georgia Wednesday through Thursday afternoon, where a Flash Flood Watch has been posted. Strong to severe thunderstorms will be possible across northeast and north central Florida on Thursday afternoon, where strong southwesterly surface and transport winds will result in high dispersion values .HYDROLOGY... Moderate flooding continues along portions of the Altamaha River, with water levels continuing to fall at Charlotteville, Baxley and Doctortown. Water levels have crested at Everett City. Minor flooding continues along portions of the Satilla River basin. Rainfall this week at upstream locations may exceed 4-6 inches, which may result in substantial rises beginning during the upcoming weekend. Local interests should closely monitor the latest official forecasts which will be further refined as the week progresses. && .PRELIMINARY POINT TEMPS/POPS... AMG 64 69 55 64 45 / 70 80 70 90 10 SSI 63 71 58 69 48 / 60 70 50 90 40 JAX 65 82 61 80 50 / 20 40 30 70 50 SGJ 66 82 63 79 54 / 10 20 10 60 60 GNV 65 84 66 81 51 / 10 10 20 70 40 OCF 64 84 66 83 54 / 10 10 10 60 50 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...Flash Flood Watch from 7 AM EST Wednesday through Thursday evening for Appling-Atkinson-Bacon-Coffee-Jeff Davis- Northern Ware-Pierce-Wayne. AM...None. &&
Area Forecast Discussion
National Weather Service North Platte NE
530 PM CST Tue Mar 3 2020 .SHORT TERM...(This evening through Wednesday night) Issued at 240 PM CST Tue Mar 3 2020 Forecast concerns in the near-term revolve around elevated fire weather conditions Wednesday afternoon across portions of western Nebraska. A bit of a chaotic start to the forecast period as the local area is caught between a quickly southward diving clipper-like system and more stout h5 cut-off trough along the southern International border. The latter of these features will remain well south of the area but the approaching disturbance currently over the western Dakotas will encroach on the north central Nebraska counties this afternoon and evening. This system will be bringing a pocket of modest moisture with it and thus have some Slight Chance to Chance PoPs for areas along and east of a Springview to Bartlett line. Forecast soundings, most notably the RAP and HRRR, indicate substantial dry air in the low levels, limiting the potential altogether as this wave moves through. Colder air aloft within the wave will produce some modest lapse rates and potentially enough elevated instability to yield some isolated thunder. Thinking potential for this too low at the moment so left out of the forecast. Further south and west, more removed from the greatest source of lift, dry air should limit precipitation to nothing more than sprinkles. All activity will clear the area by late tonight. Modest cool front will pass through tonight, preventing boundary layer from totally decoupling across the area. Expect lows generally in the 20s to low 30s further east. Wednesday will see us add a few more degrees to the daytime highs. As a surface trough passes through the area, surface winds will be on the increase out of the southwest helping to usher in warm air. Temperatures at h85 will approach the 8 to 12 degree C range, or near the 90% moving average for LBF upper air data. Nearly unidirectional surface to h85 winds will also promote momentum transfer of strong gusts to the surface. With little in the way of cloud cover, should see efficient mixing of the boundary layer helping to mix those gusts to the surface. These types of setups tend to favor temperatures warmer than guidance usually indicates and so went with the warmest guidance plus a degree or two for daytime highs. This covers most the area in the upper 50s to 60s, or values that are 15 to 20 degrees above normal for early March. Believe wind gusts will reach as high as 30 to 35 mph as well. With all these conditions and collaboration with neighbors, decided to expand and update the Fire Weather Watch to a Red Flag Warning from noon to 6pm CST for much of the Sandhills into southwest Nebraska. A second cool front will move through the area mainly during the evening hours Wednesday and with strong pressure rises behind this boundary, will see strong winds continue into the evening hours and limit overnight recovery of humidity. With these strong winds, did increase Thursday morning lows slightly but expecting values to still fall into the 20s and 30s. .LONG TERM...(Thursday through Tuesday) Issued at 240 PM CST Tue Mar 3 2020 Beginning 12z Thursday. Slightly cooler temperatures are expected for the daytime on Thursday as more Canadian are invades the area. Temperatures will still be seasonable for early March, however, as highs climb into the upper 40s to low 50s. Our dry weather looks to continue into the start of the weekend as ridging develops across the Rockies and mid-level heights rise through Saturday. Ridge axis looks to settle in by early Saturday. Temperatures will be on the upward trend with widespread 70s expected by Saturday. Ridging will begin to breakdown Saturday into Sunday as the next weather producer moves onshore the west coast and onto the High Plains Sunday. General NWP consensus is a modest surface low pressure system develops across northern Nebraska during the day and quickly treks east during the afternoon. At the surface, a well pronounced surface cool-front will push through the area as surface high pressure builds in over the upper Midwest. Some model guidance is slow to develop the surface low, keeping the highest PoPs south and east of the local area. Given some uncertainties, did decide to limit PoPs to Chance for now with the hopes that NWP guidance can hone in on more precise timing and strength of the system, thus allow confidence to increase. What is more certain is that a cooldown is expected for Monday and Tuesday with the increased cloud cover and precipitation chances with highs closer to normal during this time. Temperatures will then be quick to rebound beyond the middle of next week as ridging looks to redevelop. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 530 PM CST Tue Mar 3 2020 Mainly VFR conditions are anticipated through the forecast period, although a couple aviation weather concerns arise. Scattered mid level clouds with a few light rain showers and gusty northwest surface winds will dissipate shortly after sunset this evening. However, low level wind shear conditions are possible are overnight. A lull in the winds is expected around daybreak, then speeds pick up again out of the southwest late in the morning. && .FIRE WEATHER... Issued at 240 PM CST Tue Mar 3 2020 Elevated fire weather conditions are anticipated for the remainder of Tuesday afternoon with elevated to critical fire weather conditions expected Wednesday afternoon across much of western and southwest Nebraska. Daytime highs Wednesday will climb into the upper 50s and 60s, which is 15 to 20 degrees above normal. Sunny skies will allow for ample daytime mixing, yielding gusts in the 30 to 35 mph range and humidity values in the 15-20% range for most locations along and west of Highway 83, with localized areas potentially seeing lower. Fuels are reporting as ready to burn according to partners and collaboration with neighboring offices led to the decision to update and upgrade from a Fire Weather Watch to a Red Flag Warning during the afternoon hours. As a surface front approaches from the northwest by late afternoon/evening, winds will shift to the northwest with gusts of 25 to 30 mph likely to continue through the overnight hours. This will limit overnight humidity recovery, with many locations seeing minimum humidity values remain at or below 60%. && .LBF WATCHES/WARNINGS/ADVISORIES... Red Flag Warning from noon CST /11 AM MST/ to 6 PM CST /5 PM MST/ Wednesday for NEZ204-206-210-219. && $$ SHORT TERM...Jurgensen LONG TERM...Jurgensen AVIATION...Snively FIRE WEATHER...Jurgensen
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
805 PM CST Tue Mar 3 2020 .UPDATE... 805 PM CST Guidance has trended slightly farther south with the focus for a brief period of snow late tonight into Wednesday morning, in line with observational trends across eastern SD and western IA this evening. Have made a 20-40 mi southward shift with the axis of higher snowfall, focusing roughly around and just north of the I-88 corridor. A quick inch of slushy snow is possible primarily in the 3- 7am window. Some concerns do exists that the precip focuses into a very narrow 20-30 mile W to E corridor where totals could be enhanced slightly. Will continue to monitor trends tonight, but expect some minor localized impacts for the morning commute, with air temps at or above freezing likely limiting the potential for higher impacts. Kluber && .SHORT TERM... 315 PM CST Through Wednesday... Another fast-moving clipper system will quickly return the potential for precipitation to the region later tonight into Wednesday morning, with some accumulating light snow possible especially north of the I-80 corridor. In the near term, mid-level trough associated with this morning`s clipper was moving off to the east this afternoon. Mid-level cold pool associated with this departing system, combined with a deeply mixed boundary layer, has led to development of scattered showers across eastern parts of the forecast area this afternoon. RAP soundings/meso-analysis even depict 100-200 J/kg of SBCAPE, which has produced some graupel as well as perhaps a rumble of thunder from some of the deepest cores over northwest IN, which are now moving east of the cwa. As this system exits stage right this afternoon, clouds will decrease and blustery west winds currently gusting to 35-40 mph will diminish. Attention then quickly turns to another clipper system, noted in afternoon water vapor imagery digging southeast out of eastern Montana. This wave is progged to continue southeast tonight, amplifying its associated mid-level trough across our area by Wednesday morning. As this disturbance approaches the area later tonight, backing low-level flow will induce a period of warm advection and frontogenesis which will enhance an elevated baroclinic zone across far northern IL/southern WI. This forcing will develop beneath a region of fairly steep (7-7.5 C/km) mid level lapse rates, leading to quick saturation and likely a period of precipitation developing after midnight and persisting into the early-mid morning hours of Wednesday. Guidance still shows some minor differences with the details of the QPF axis, which looks to be a relatively narrow west-east band across northern IL/southern WI into northwest IN, but does focus the potential across our cwa especially along and north of the I-80 corridor. Thermal profiles generally support snow in those areas, with a rain/snow mix farther south. Several things make for a slightly lower-confidence snowfall amount forecast, including mild ground conditions, the relatively short duration of snow, and also the potential for narrow banded areas of heavier intensity snow. Generally however, from the I-80 corridor northward am expecting between a few tenths to perhaps an inch or so in some spots. System exits quickly to the east Wednesday morning, with sunshine, breezy northwest winds and above-freezing temperatures expected to start melting snow quickly. Persistent cool advection will limit highs to around 40/low 40s north, while southern parts of the forecast area are expected to warm into the upper 40s again. Quiet weather continues Wednesday night, as high pressure builds in. Ratzer && .LONG TERM... 315 PM CST Wednesday night through Tuesday... Another in a series of short wave disturbances along the polar jet is progged to dig southeast from the northern Plains and amplify across the Great Lakes region Thursday through Friday. Associated surface low pressure reflection passes north of the forecast area during the day Thursday, with it`s trailing cold front pushing east across the cwa during the day. Forecast soundings depict a fairly dry thermodynamic profile in advance of the front, with relatively shallow saturation developing mainly across northern/eastern parts of the cwa with the frontal passage as cold advection cools the column. Timing of cold fropa during the midday/early afternoon hours with temps in the 45-50 degree range will result in p-type of rain/showers, with strong drying then developing behind the front and shutting off precip. More noticeably, windy conditions are again expected with south- southwest winds gusting 30-35 mph ahead of the front in the morning, then of 35+ mph from the west during the afternoon behind the front. As the wave and surface low continue to move southeast toward the upper Ohio Valley into Friday morning, a secondary surface trough/cold front will move across the area, with gusty winds turning more north-northwest. This will build larger waves (in excess of 8 feet) into the Indiana shore of Lake Michigan, and would likely result in a period lakeshore flooding during Thursday night and persisting through Friday. Winds diminish quickly later Friday, as surface high pressure builds in to the area from the west. Friday looks to be the coolest day of the entire forecast period, as strong cold advection limits highs to near 40/low 40s in most areas. Upper level high pressure ridging then develops across the Midwest into the weekend, in the wake of the departing eastern trough and downstream of troughing along the west coast. This will produce a period of dry breezy and much warmer weather across the region, as south flow becomes reestablished as surface high pressure ridge drifts east of the area on Saturday. Persistent warm advection pushes 925 mb temps to +5/6C Saturday, and to around +10C on Sunday, which should support 50s for highs Saturday and temps in the 60s for Sunday and our blended guidance is appropriately a little warmer than EC and GFS MOS numbers, especially for Sunday. Precipitation potential then looks to increase as early as Sunday night and more likely Monday, as medium-range guidance is in decent agreement in bringing short wave energy out of the western trough. Moisture feed from the western Gulf of Mexico also increases into Monday, as deep south-southwesterly flow persists ahead of an approaching cold frontal trough and surface low pressure wave associated with the approaching short wave. Though some timing differences exist between the different models with the passage of the cold front, precip potential should peak generally during the Monday-Monday night period. Depending on the timing of the front, Monday has the potential to be another fairly warm day, with highs in the 50s to near 60 east of the front. Upper level flow is then progged to flatten across the region Tuesday and Wednesday, which allows the front to become nearly stationary somewhere south of the forecast area. ECMWF is stronger with high pressure building across the area Tuesday, pushing the front farther south. GFS and CMC are weaker with the ridge, and are not quite as far south with the position of the front. Both the GFS and CMC also spread precipitation back into the area by Tuesday night, as they develop another stronger low which tracks along the front into the region mid-week. For now, the main message is for somewhat cooler weather by Tuesday, with a lower but non-zero potential for additional rainfall. Ratzer && .AVIATION... For the 00Z TAFs... Main change for this forcast package was a tweak in how snowfall is handled for Wednesday morning. This may not be the correct tweak...but the idea was to slide the start just a bit later, include SN as prevailing with MVFR cigs and vsbys, then include lower conditions in a short 2hr tempo group around the time when the peak activity is expected. Overall this brief period of light snow, probably mixed at times with rain, is not expected to pose significant impacts. Any minor accumulations would likely be on grassy areas rather than roads and runways, and that should quickly melt as the day warms into the 40s. Otherwise, gusty west winds diminish tonight and turn southwesterly, then veer northwesterly again during the morning after the snow passes. Lenning && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...Small Craft Advisory...nearshore waters until midnight Wednesday. && $$ Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Pocatello ID
144 PM MST Tue Mar 3 2020 .SHORT TERM...Tonight through Thursday night. Expect light snow and freezing drizzle in the eastern highlands through Wednesday. Could see an additional inch or two in the Island Park area with some potential for light freezing drizzle mixed in. Temperatures are above freezing so could see some travel issues as temperatures drop below freezing after sunset. Remainder of the region will be dry through Thursday night with warm temperatures. Expect well above normal temperatures continuing through the week with temperatures in the Eastern Magic Valley and Lower Snake Plain approaching 60 by Thursday. Expect 15 to 20 mph winds Wednesday in the Eastern Magic Valley and Snake Plain from Burley through Pocatello. Winds should be lighter on Thursday. GK .LONG TERM...FRIDAY THROUGH NEXT TUESDAY... Few changes were made in the long-term portion of the forecast. Confidence remains highest Fri, as high pressure will provide dry and warm conditions especially across the Magic Valley, lower Snake Plain, and srn highlands where highs may reach the mid 50s to lower 60s! Our next trough of low pressure remains on tap for the weekend, spreading snow into the Central Mntns Sat morning, and then predominantly rain across the rest of the region Sat afternoon. Snow levels will be running 6,000 to 6,500 feet. Precip trends toward all snow late Sat night/Sun with snow levels falling toward 4,500 feet. Some model differences remain in the strength of the cold front Sun AM. An early look at storm total snow accumulations suggests an inch or less below about 6,000 feet where rain will dominate for the first half of the event, and generally 1-6 inches as you go up in elevation with localized higher amounts above the passes. We`re getting into the time of year when the sun angle and slightly warmer ground/pavement temps may help us as well as far as reducing impacts. At this time, the area that is forecast to see precipitation sticking around long enough by the time the colder air arrives is the eastern highlands and Bear Lake areas -- and these areas have the highest accumulating snow potential Sun. Slightly cooler weather with predominantly mntn snow showers remain Mon/Tues as a secondary trough swings through. - KSmith .AVIATION... Generally VFR cigs/vsbys are expected. At KIDA, there is some suggestion in the guidance that the lower atmosphere may be moist enough to allow some low stratus to develop early Wed morning, and we did go ahead and include this in their TAF starting at 10z, although confidence is a bit low. The HRRR is advertising fog development as well near the terminal, but leaned away from this as winds may remain 5-8 knots which generally is a little high for fog. We will watch trends closely. At KDIJ, we also broadbrushed some VCSH throughout the TAF period (which would be snow), but confidence was not high enough in snow getting into the terminal to upgrade beyond VCSH. Snow showers may also be light enough to keep vsbys from falling below 6SM. MVFR cigs are possible. - KSmith && .PIH WATCHES/WARNINGS/ADVISORIES... None. && $$