Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/14/19


Area Forecast Discussion
National Weather Service La Crosse WI
646 PM CDT Sun Oct 13 2019 .SHORT TERM...(This evening through Monday) Issued at 233 PM CDT Sun Oct 13 2019 Local and regional radars this afternoon continue to show some pockets of snow/rain showers over areas along and east of the Mississippi River. These are mainly being driven by the steep low level lapse rates and weak omega in the cyclonic flow. Expect that these will end early this evening as the boundary layer cools and the lapse rates become less favorable. The next concern then becomes when or if the clouds will clear out any overnight. Both the 13.12Z NAM and 13.15Z RAP show lots of low level moisture trapped under the inversion in the cyclonic flow with the clouds extending all the way back into the Dakotas. This low level cyclonic flow really does not start to relax until very late tonight across the southern sections as an area of high pressure moves across Iowa. If this clearing does occur, still some doubts whether is would occur early enough to allow for much frost to form or for temperatures to drop much below freezing. With these unknowns, do not plan to issue either a frost advisory or freeze warning but will issue a special weather statement to highlight the potential. The clouds should then clear from south to north through the day Monday as the area of low pressure over Ontario continues to pull away from the region. With some sunshine, look for warmer temperatures with highs in the 40s and lower 50s expected. .LONG TERM...(Monday night through Sunday) Issued at 233 PM CDT Sun Oct 13 2019 Brief dry period will come to an end as a shortwave trough and surface low/cold front move in for Tuesday. Rain chances increase west to east Tuesday morning and continue into early afternoon. At this time the greater amounts look to be to our north and east, however, as the low becomes better organized after passing through our area. With a small amount of CAPE (100-300 J/kg), there may be some isolated thunder as well. Lingering wrap-around precipitation may affect parts of western/north-central Wisconsin through the evening, but should end by Wednesday as the low moves east. Conditions will be cool Wednesday(highs mainly in the 40s). The area will be on the northern fringe of high pressure centered across the southern plains for mid to late week, setting up a stretch of drier weather through at least Friday afternoon. As the high drifts east, southerly return flow Thursday and Friday will allow temperatures to climb back up into the 50s and 60s. Next shot at rain comes Saturday, as a shortwave moves across the area. Following this system, models show upper level troughing and an area of low pressure moving into the Upper Midwest for Sunday/early next week, but large placement and timing differences remain. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 639 PM CDT Sun Oct 13 2019 Light rain or snow showers look to linger for the next hour or so across the area, with VFR ceilings sticking around through this evening. Ceilings upstream vary from MVFR to VFR as moisture associated on the southern fringes of an expansive low encompasses much of the Upper Midwest. Held on to VFR ceilings, but added a group of lower scattered clouds tonight as confidence is low in what the ceilings will do. Will have to monitor closely, but may need to be adjusted with time, or with the next TAF issuance. West winds lighten up this evening and stay light through the TAF period while gradually backing to a more southerly direction by Monday evening. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...04 LONG TERM...Lee AVIATION...NMB
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
628 PM CDT Sun Oct 13 2019 .DISCUSSION...Updated for latest aviation discussion below. && .AVIATION...Satellite images and surface observations indicate some low level clouds across northern portions of the CWA early this evening with clear skies across eastern portions of the Rio Grande Valley. Ceilings were near 1500ft at KBKS to near 2500ft at KHBV. Expect VFR conditions to prevail across the Rio Grande Valley tonight into early Monday morning even as a weak coastal low moves northward along the lower Texas coast. && .PREV DISCUSSION... /issued 301 PM CDT Sun Oct 13 2019/ SHORT TERM (Tonight through Monday Night)... The relatively "cool" weather has been a nice break from what had been "endless summer" across Deep South Texas and the Rio Grande Valley (with average temperatures through the 10th running up to 6 degrees above normal, ranking in the top five in several locations). That cool-ish weather continued today for many inland locations, were temperatures have only reached the mid 70s as of 230 PM. Toward the coast, partial clearing allowed a bump into the lower 80s. Each of these trends have been accounted for in a mid afternoon update, which both lowered forecasts inland and raised them near the coast in southeast Cameron County. Hereafter through Monday night, the summer sultriness returns...gradually overnight and more robustly Monday through Monday night. For tonight, deeper moisture along a pseudo warm front remains/shifts north of the region, with perhaps a tail of moisture continuing through Jim Hogg/Brooks southeast to the Lower Texas Gulf waters. Left the slight chances for the overnight...matching guidance consensus. Confidence not very high...and overall precipitation would be passing light showers with minimal impact. Otherwise, the only other concern is potential for patchy to areas of fog. With light to calm winds and recovery of warm/humid air expected to raise dewpoints over neutral temperature ground...and considering length of day...ingredients are in place for some fog across rural areas. Based on a look at HRRR deterministic and HREF probabilistic forecasts for low visibility, introduced patchy wording across the brush country. Signal less clear across the Valley so left out for now. Any fog will burn of by 9 AM or so Monday, and any notable forcing for precipitation shifts north. What`s left is the potential for isolated streamer showers/few storms mainly in the Gulf. Current forecast of 90 to 95 from east to west was left alone...a lean toward the ECMWF which has done best through this summer and early fall when the heat is on. The soup arrives in full Monday night as light gentle southeast breezes return. Those breezes should end any fog threat though sometimes the northern ranchlands can see development. Lows will be similar to those last work week (lower to upper 70s)...10 degrees above average for mid October. Overall deep dry air sufficient for no mentionable rainfall. LONG TERM (Tuesday through Sunday)...A strong ridge of high pressure aloft anchored across the CWA on Tuesday will boost temps well above normal. Limited moisture and subsidence will keep things dry as well. A cold front is expected to move slowly southward overnight Tuesday, reaching the northern ranchlands by Wednesday morning. A gradual push south across the CWA is expected on Wednesday. Sufficient moisture aided by an accompanying shortwave will boost PWATs up to 2.2 inches on Wednesday. Dynamical forcing from this shortwave and the RRQ of an upper jet streak along with kinematic forcing are expected on Wednesday. As a result, will go with at least chance to likely POPs for much of the CWA for Wednesday and Wednesday night. With the front expected to stall near or just south of the CWA on Thursday, decent rain chances will persist, especially across the southeast areas and the adjacent waters given the strong coastal troughing in this region. A bit of a drying trend is expected for the end of the week as another shortwave moves through the CWA and advects the deeper moisture east and northeast of the CWA. Not totally convinced that we will completely dry out and so will tend to keep slight chance to chance POPs for mainly eastern areas. Will indicate a warming trend during this timeframe as the airmass really begins to modify quickly. An influx of deeper moisture on Sunday ahead of the next strong cold front will maintain chance POPs. NHC and some NWP output has been indicating the small potential of a weak low pressure area developing across the southwest Gulf/Bay of Campeche towards the end of the week. Even if this scenario does pan out, the westerly shear will keep any such system weak and likely remain east and northeast of the CWA. Indirectly, it will only likely contribute to the continuing elevated water levels and resulting minor coastal flooding. MARINE...Much has quieted down since Friday afternoon-Saturday with moderate seas and light to moderate winds. As gradients collapse completely overnight (coastal trough dissipation) winds should drop to 10 knots or less on the Gulf and nearly calm over the bay. Southeast winds generally 10 knots or less Monday with the usual afternoon increase over Laguna Madre...then gradient picks up overnight over the Gulf but still 15 knots or less...with seas remaining at 3 feet or less though wind waves will increase a hair. Otherwise...scattered showers/few thunderstorms tonight fading to isolated streamers (mainly Gulf) Monday and no mentionable precipitation Monday night with deeper dry air in place. Brief SCA conditions will be possible on Wednesday across the offshore waters as the next cold front moves south across the CWA. Coastal trough development Wednesday night through Friday morning will contribute to numerous to widespread showers and thunderstorms over the waters. A weakening of the coastal trough by the end of the week will diminish winds and seas and also rain chances. Rain chances will increase once again by Sunday as another surge of moisture occurs ahead of the next strong cold front early next week. && .BRO WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ This product is also available on the web at: HTTP://WEATHER.GOV/RGV 61/56
Area Forecast Discussion...UPDATED
National Weather Service Gray ME
939 PM EDT Sun Oct 13 2019 .SYNOPSIS... Low clouds and patchy fog will increase again tonight, lasting into Monday, mainly on the coastal plain and inland Mid Coast. A vigorous low pressure system is likely to move across the forecast area starting Wednesday, and may allow for a period of heavy rain and windy conditions Wednesday night into Thursday. High pressure will slowly build over the region from the west Friday and into the weekend. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... 940 PM Update... Calm fall night in progress and have made just a few changes for falling dew points across the mountains. Fog should be widespread across the coast and portions of the interior and perhaps dense at times in the morning. 8 PM Update... Temperatures have dropped into the mid 40s across the north and the lower to mid 50s south. Dew points have also dropped into the mid 30s across the mountains which is helping to foster cooling temperatures. HREF and HRRR are still supporting stratus clouds moving in from the waters overnight. Only a few minor changes to the forecast so far as it is on track. 515 PM Update... Forecast is on track except for some warmer readings realized this afternoon thanks to rapid cloud clearing. Across the north, lower dew point readings were observed versus the forecast, so will have to monitor for temperatures trends tonight as temperatures may come down cooler than forecast over western Maine. Also extended the SCA for southern most two marine zones with observed waves up to around 6.5`. Previously... Mid-level ridging provides a nice day locally with temperatures climbing a couple degrees above average and some Mid Coast cloud cover. Meanwhile further west, a strongly forced closed low churns over the Great Lakes region and central Ontario. Tonight, heights aloft begin to fall as a shortwave axis rotates around the closed low toward New England. Hires guidance including the HREF continues to suggest onshore low-level flow/weak positive moisture advection developing overnight with high pressure moving offshore. This will likely lead to a blanket of low stratus and fog by Monday morning along coastal NH and ME, further into the coastal plain in ME with greater southerly component to flow. Temperatures are a bit tricky tonight; decoupling is likely early on, leading to quick cooling after sundown, but then cooling slows or is halted altogether with moist onshore flow. Therefore, coolest readings in the 30s and perhaps fog will likely be in sheltered valley locations of the north and into portions of the Connecticut River Valley. Warmest readings are likely in coastal ME/NH. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... Southwest flow increases, as will available moisture, in response to an approaching shortwave trough Monday. This ought to lift ceilings in the morning, however widespread status to stratocu cover is expected persist through much of the day. Moisture convergence may be strong enough to produce a brief, light shower on the Mid Coast in the early afternoon. Modestly higher dew points work in through the day, as does warmer 850mb temps at 5-7C, however cloud cover will be the determining factor for high temperatures tomorrow. Should breaks in the clouds allow for mixing and solar insulation, temperatures could easily increase into the low-70`s across the south. Don`t have a ton of confidence in cloud breaks tomorrow however so stuck fairly close to a raw model consensus with higher values closer to MOS guidance across southern NH where cloud breaks are more likely. While deep moisture remains offshore and to the southeast, enough forcing along a crossing cold front Monday evening into the overnight could still produce a few light showers especially across the north and in the mountains of ME/NH. Models and WPC eke out only a tenth or two of rain with the crossing front. && .LONG TERM /TUESDAY THROUGH SUNDAY/... High pressure will briefly build over the region Tuesday. This will allow for mainly sunny and dry conditions. Temperatures will be seasonable for mid October, mainly in the 50s. All eyes then shift towards low pressure moving east from the Great Lakes Tuesday night into Wednesday. 12Z model suite and ensemble solutions continue to a secondary area of low pressure over the Mid Atlantic states late in the day Wednesday. This system will track off the New Jersey coastline Wednesday evening, before racing into southern New England Wednesday night. During this period, rapid cyclogensis occurs with the low plummeting to around 975 mb by the time the center reaches approximately Portland, Maine by early Thursday morning. Heavy rain will fall along and to the left of the H7 and surface low. One to two inches of rainfall expected, however locally higher amounts are possible over the east facing mountains. The Canadian model QPF is at the high end of the spectrum, likely because its track is slightly further east then other model solutions, therefore any dry slotting is delayed. Cloud cover will keep temperatures in the 50s for daytime highs on Wednesday. Cold air advection under gusty westerly winds will keep temperatures in the mid 40s to mid 50s for high temperatures from north to south on Thursday. Breezy conditions will continue into Friday as the low slowly exits through the Canadian Maritimes. Thereafter, high pressure will build into the region over the weekend. This will allow for dry conditions and moderating temperatures. && .AVIATION /02Z MONDAY THROUGH FRIDAY/... Short Term... VFR prevails with light winds for the remainder of today. Tonight, most guidance has consistently pointed toward low stratus development as a likelihood especially over the Mid Coast with weak, moist onshore flow as high pressure shifts into the Gulf of Maine. While some radiation fog is expected to develop tonight over the Connecticut River Valley, patchy dense fog and MVFR or worse (IFR near dawn) ceilings are more likely to develop at coastal and Mid Coast terminals. MVFR, and some brief instances of IFR, ceilings may linger through the day with scattering likely in the afternoon. Then, a cold front crosses tomorrow night with improving conditions to follow as high pressure nudges in from the west Long Term...Increasing clouds expected on Wednesday with rain arriving from west to east Wednesday evening. Will likely see a period of IFR conditions and moderate rainfall along with some wind shear. This ends from west to east early Thursday morning as low pressure moves east. Behind the low expect gusty west to northwest winds of 25 to 30KT especially Thursday morning. Otherwise, we should see conditions improving to MVFR and VFR Thursday and Thursday night, with the lower conditions lasting longest in the mountains. && .MARINE... Short Term...Waves and swells continue to come down tonight with remaining SCAs on track to expire this evening. Light northwest winds turn variable to southerly tonight, becoming southeasterly onshore at 5-15 kts by Monday evening as a wave aloft and associated cold front approaches. The front crosses Monday night with a switch to westerly winds to follow. Long Term...High pressure crests over the Gulf of Maine on Tuesday. The next low pressure system tracks up the East Coast on Wednesday and strengthens rapidly when it reaches the Gulf of Maine Wednesday night. Expect southeasterly winds to back to the northeast Wednesday night. Gale force westerly winds possible on Thursday behind the departing low. && .HYDROLOGY... Low pressure will undergo rapid intensification as it moves quickly to the northeast Wednesday night. One to two inches of rain will be likely as the surface and H7 moves from southern New England to southern Maine. Some of the east facing locations across the higher terrain of the headwaters may have locally higher amounts. This precipitation in such a short amount of time may allow for rapid rises on a few of our rivers. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory for hazardous seas until midnight EDT tonight for ANZ154. && $$ NEAR TERM...Hanes
Area Forecast Discussion
National Weather Service Marquette MI
657 PM EDT Sun Oct 13 2019 .SHORT TERM...(This evening through Monday) Issued at 416 PM EDT SUN OCT 13 2019 Similar conditions today as there were yesterday, as our low pressure system begins moving across Northern Lake Superior. As seen in RAP analysis and GOES WV, there are a few embedded waves cycling through this low, kicking off -SHRASN throughout much of Upper Michigan. Upper Michigan has not seen some of the steadier bands that some high-res models were suggesting, but ASX has seen a steady band overhead just west of IWD. A band to the east across APX`s cwa has steadily brought -SHRA to eastern Upper through this afternoon, with some showers finding their way into Schoolcraft and Luce counties. For tonight, as the next embedded shortwave continues to kick winds around expect some additional lake-effect snow and rain showers to kick off for the NW wind belts. With winds across eastern Upper slowly veering more westerly expect this band to slowly diminish while inching eastward. Depending on how the bands and shortwave showers go, expecting somewhere along 1 to 2 inches tonight across western Upper Michigan. However, this does seem like a scenario where we can also get nothing if high-res guidance is off track. Guidance for low temperatures tonight are among good agreement, with 10th percentile and 90th percentile within 4-5 degrees. Felt comfortable going right with the median based off last night`s performance and similar airmass overhead. High-res models have not been handling today all too well, but do suggest some clearing tonight across south-central and along Lake Michigan. Overall, the chance for an inch or two of snow in west and central UP, with temps in the upper 20s in usual cool spots to low 30s elsewhere. On Columbus Day, the shortwave continues eastward as heights begin to rise in the afternoon. PoPs left from overnight will slowly dissipate as winds back more westerly, cutting off lake-effect flow downstream. With some clear skies expected tonight into tomorrow, based on high-res guidance, south-central UP and east into ERY may warm up into the upper 40s with low 40s expected in the west. .LONG TERM...(Monday night through Sunday) Issued at 445 PM EDT SUN OCT 13 2019 Models suggest that a progressive pattern will prevail with mid/upper level troughing into the Great Lakes giving way to ridging toward the end of the week and sw flow this weekend as heights lower across the western CONUS. Cold conditions will moderate with above average temps from Friday into the weekend. Monday night, moist low level westerly flow with 850 mb temps around -3C will support lingering sct -shra through eastern Lake Superior that may brush the far northeast, near Whitefish point. Otherwise, increasing clouds ahead of the approaching shortwave trough will keep temps from falling off as much late with readings climbing at or above freezing. Tuesday into Tuesday night, the models were in good agreement that the vigorous shortwave trough from the northern Plains will dig into the western Great Lakes. Moderate to strong 700-300 qvector conv with this feature will support rain spreading across Upper Michigan during the morning that will continue into through the evening. Rainfall amounts across much of the area around 0.50 inch is expected. However, lake enhancement with strong convergent winds veering from ene to n and 850 temps to around 0C will bring heavier amounts north central, likely into the 1.00-1.25 inch range. Higher terrain locations could see even greater amounts. Wednesday, lake effect/enhanced rain showers will continue north as winds only slowly veer from n to nnw as 850 mb temps drop to -4C. Some improvement may be possible by afternoon as the deeper moisture slides to the east. Otherwise, blustery north winds will continue over the east half with temps remaining in the 40s. Thursday, with mid level and sfc ridging building into the area, expect thinning clouds with some sunshine by afternoon. Highs should still remain in the upper 40s to around 50. Fri, WAA will increase ahead of a mid level shrtwv and sfc trough moving toward the Upper Mississippi Valley. Although clouds will increase with the potential for some light rain late, the WAA will also help temps rebound into the 50s. Sat-Sun, model differences were larger in handling the timing/amount of pcpn into Sat as the ECMWF/GEM were faster and weaker compared to the GFS/GEFS. So, only chance POPs were mentioned. A stronger shortwave and sfc low is expected to develop and approach the western Great Lakes by late Sunday or Sunday night with more substantial rain possible. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 656 PM EDT SUN OCT 13 2019 Transient snow showers will continue tonight at IWD and CMX from lake effect while SAW will see some snow showers this evening until the wind turns west enough to keep the snow to the north of the site. Expecting mostly MVFR conditions in the snow showers. Conditions will improve to VFR at SAW overnight with a west wind and at IWD by Mon afternoon. CMX will be mostly VFR through the period. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 416 PM EDT SUN OCT 13 2019 Low pressure from the last few days is beginning to move east of Lake Superior this afternoon. Winds have veered more west to northwest, relaxing gusts to 20 to 25 knots. With slight ridging overnight on Monday, winds will relax below 20 knots as another wave approaches from the Central Plains. As the gradient tightens, NW winds gusting up to 30 knots on Wednesday is possible. Another slight ridge will pass on Thursday as a low passes to the north of the lake on Friday. Southerly winds pick up to 25 knots on Friday lasting into the weekend as another low pressure system approaches. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...JAW LONG TERM...JLB AVIATION...07 MARINE...JAW