Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/05/17


Area Forecast Discussion
National Weather Service Billings MT
820 PM MDT Wed Oct 4 2017 .UPDATE... An area of light rain exists from Billings westward toward the Crazy Mountains, and showers are beginning to develop near Hysham and Lame Deer. This activity is in response to ascent provided by shortwave lifting out of a slow-moving parent low over the northern Great Basin. Have adjusted evening pops to cover radar trends. Overall this activity should slide north over time tonight, and mostly diminish by sunrise, as descent works in from the southwest behind the wave. With at least some partial clearing expected in our western cwa overnight, cannot rule out some patchy fog as the current precipitation is helping to moisten the boundary layer (current dew points are in the mid- upper 30s). The HRRR is not suggestive of fog at this time. Will be another fairly chilly night with lows in the 30s. JKL && .SHORT TERM...valid for Thu and Fri... Upper low over Idaho will swing some energy through our CWA tonight. Moisture is mainly at the mid levels, but lapse rates are steep enough to support rain/snow showers over the mountains and isolated shower activity over the plains, maybe even a little thunder here or there. The jet stream nosing into the SE zones may even support a band of precipitation Thursday night and into Friday, but by late Friday the upper low weakens and its axis shifts east to the Great Plains. Look for warmer temps Friday in its wake. We are in the autumn season so things will transition quickly Friday night. The northern jet quickly drops south into northern Montana with a tight pressure gradient developing southeastward into our area. Our western foothill locations will likely see the first effects, particularly at the gap locations (Livingston, Nye). There is potential for wind advisory criteria Friday night into Saturday at these sites. As a matter of fact, by late Friday night/early Saturday morning strong 850MB wind fields are progged to spread across NW to SE across our central and eastern zones. The westerly jet stream will be nosing right across east central Montana at this time with downward motion in the front right quad over our eastern zones. Lapse rates suggest these winds could impact areas from eastern Musselshell to northern Custer County with strong gusts. See long term discussion below for further information on winds this weekend. We will begin messaging the windy conditions in some of our other products and on our website. BT .LONG TERM...valid for Sat...Sun...Mon...Tue...Wed... Only a few minor tweaks to the inherited long term forecast, as overall story remains consistent. Timing of models for Saturday appears in better agreement for later FROPA, resulting in warmer temps across the region. Therefore, trended temps upward for Saturday, with highs around 70 in most locations across the plains. It continues to look windy for Saturday, both before and after FROPA, with gusts over 60 mph in the western foothills pre- FROPA, and a windshift and gusty northwest winds to follow FROPA across the plains. Expect to see scattered showers for a couple of days following, with snow in the mountains, which could drop into the lower elevations during the overnight hours. There could be a few thunderstorms mixed as well on Sunday afternoon. The airmass in place for Sunday and Monday looks quite cool, with 850mb temps of 4 to 5 C, pointing to highs in upper 40s Sunday. Strong West Coast upper ridge builds into the area late on Monday providing a bit of a warm up to get temps back into upper 40s. Dry and breezy conditions can be expected for Monday evening through Wednesday under the ridge. Temps will trend upward through the end of the forecast period. On the far horizon models starting to hint at a significant cold air intrusion late next week. Models do differ, but agreement is reasonably good for this far out in time. We will be watch this development closely ver the next week or so. AAG && .AVIATION... Expect mainly VFR conditions to prevail. Scattered showers are moving from southwest to northeast across the area and will continue to overnight. Brief MVFR conditions are possible with these showers. Some patchy fog is possible mainly after 06z, especially around KLVM. Reimer && .PRELIMINARY POINT TEMP/POPS... Thu Fri Sat Sun Mon Tue Wed ----------------------------------------------------------- BIL 036/056 037/067 046/069 039/050 033/048 029/053 037/058 50/B 00/U 01/N 23/T 22/T 11/U 00/U LVM 032/053 032/062 042/065 034/043 026/044 026/050 032/056 31/B 10/N 01/N 24/T 32/T 11/U 00/U HDN 035/058 036/067 043/072 038/052 034/049 030/054 036/061 10/B 00/U 01/N 23/T 22/T 11/U 00/U MLS 036/056 037/066 044/069 038/052 033/047 028/049 034/057 20/U 01/U 01/N 12/T 11/B 11/U 00/U 4BQ 036/057 037/064 042/070 039/051 034/045 028/048 034/057 20/U 01/B 01/N 23/T 22/T 11/U 00/U BHK 037/057 037/064 043/068 037/052 032/043 027/047 032/054 20/U 01/U 01/N 12/T 12/W 11/B 10/U SHR 033/056 035/063 039/072 037/048 030/045 027/050 032/059 10/U 11/B 01/U 34/T 22/T 11/U 00/U && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$ weather.gov/billings
Area Forecast Discussion
National Weather Service Caribou ME
1031 PM EDT Wed Oct 4 2017 .SYNOPSIS... A cold front will cross the area overnight followed by a secondary cold front Thursday night. High pressure will build in from the west on Friday and crest over the area Friday night. && .NEAR TERM /THROUGH THURSDAY/... 1030 PM Update... A large area of rain moving across the region w/some embedded tstms. Most of the convection has started to weaken per the latest lightning data showing less strikes. Meso analysis indicated convective parameters such as MUCAPE weakening. There is still some shear noted from the latest 00z CAR RAOB of 35 kts. The RAP soundings matched close to the CAR RAOB and indicate that some elevated convection still possible up through midnight or so. The main threat looks to be some heavier bands of rain through about 2 AM. The cold front is still w of the state and expected to push through the area by Thursday morning. Some cooler air is expected to move into the region by daybreak. Decided to keep the mention of heavy rain in the forecast up through about 1 AM along w/some gusty winds. Also adjusted the QPF blending in the latest values from the NERFC bringing around 0.50 inches of rainfall to portions of the n and w. A well needed rainfall for the region. Also adjusted the pops to bring values up some across central and downeast areas. Previous Discussion... With cld cvr and not much in the way of llvl cool advcn and a WNW breeze behind the front, ovrngt lows will be mild for this tm of year. Hi temps Thu under msly sunny skies will be about 10 deg cooler across the N to 5 deg cooler Downeast than this current aftn with a fair Wrly breeze, still sig abv normal hi temps and quite pleasant for this tm of season. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... A cold front will approach Thursday evening and cross the area Thursday night. This weak secondary cold front will have very little moisture, and likely only produce a few patchy mid and high clouds. High pressure will build in from the west on Friday bringing a mostly sunny and seasonable afternoon. The high will crest over the area Friday night allowing for a clear, calm, moonlit night as temperatures fall below freezing in many northern valleys. High pressure will move east of the area on Saturday as a broad trough of low pressure approaches from the west. This will begin to channel subtropical moisture north toward our area. A warm front will lift north into the area late Saturday bringing a chance for some showers as a surge of increasingly humid air lifts north toward our region. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... The start of the extended finds the models in general agreement. A low over the southern portions of James Bay, With a warm front extended southeast into northeast Maine, the associated cold front extending south to the gulf of Mexico. A tropical low will be interacting with the southern end of the front south of MS/AL. Sunday morning the cold front sweeps through northern Maine, and will be across Downeast, the MidCoast, and Southwest Maine as it extends southwest where the tropical low will become attached to the front along the coast of MS/LA (GFS), central MS (GEM) or the Panhandle of FL (ECMWF). Higher pressure will build across Maine, The cold front will be brought back across Maine as a warm front as the tropical low moves north into the western portions of VA Monday morning. By Monday evening it will move into the Gulf of Maine south of Portland, then drift southeast to the south of Nova Scotia Tuesday morning. A low over Lake Superior Tuesday morning will move east to central Quebec by Wednesday morning bringing a cold front into western Maine. The cold front will move through Wednesday night and higher pressure will remain across the area through the end of the period. Loaded a blend to smooth out the differences in the models, however the solution leans more towards the GFS solution. Used NAWAVE4 for seas in the coastal waters. Used windgust by factor tool. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... NEAR TERM: Current VFR conditions will transition to MVFR clgs and ocnly, vsbys with shwrs this eve into the ovrngt spcly Nrn TAF sites. All TAF sites should become VFR late tngt behind the cold front and then cont so thru Thu. SHORT TERM: VFR conditions are expected Thursday night through Saturday morning. Conditions may lower to MVFR from south to north Saturday afternoon as ceilings lower ahead of an approaching warm front. && .MARINE... NEAR TERM: Will cont with the SCA for our outer MZs, with the ending extended til noon Thu, at which point, both winds and seas should begin to subside. Kept close to WW3 wv guidance for this fcst update thru Thu with primary wind wv pds of 5 to 7 sec. SHORT TERM: Winds and seas are expected to be below SCA through Saturday morning. A southerly winds will increase with the approach of a warm front late Saturday and winds may reach SCA late in the day. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...Small Craft Advisory until noon EDT Thursday for ANZ050-051. && $$ Near Term...Hewitt
Area Forecast Discussion
National Weather Service Duluth MN
840 PM CDT Wed Oct 4 2017 .UPDATE... Issued at 840 PM CDT Wed Oct 4 2017 Temperatures have been cooling quickly this evening and were lowered for most areas. We expanded the Frost Advisory across much of far northern Minnesota and will watch temperatures over the next 1 to 2 hours for possible additional expansion. && .SHORT TERM...(This evening through Thursday) Issued at 354 PM CDT Wed Oct 4 2017 At 330 PM, skies ranged from cloudy across the international border region, to mostly clear across the far south. We did have extensive cloud cover for most of the CWA today, but the clouds were starting to break up, especially across the south. Temperatures were generally in the 50s with gusty west winds. The focus for tonight is on cloud cover, and the potential for frost across portions of the region. The general consensus among the various model solutions is that the clouds will continue to clear across the Northland tonight. Most guidance indicates the coolest temps are expected to be in Koochiching and Northern Itasca county tonight, and as a result, we have issued a Frost Advisory for that area. The gusty winds will also diminish tonight, giving us further cause to issue the Frost Advisory. For the southern half of the CWA, we should see an increase in mid and high clouds as the night wears on. The big question is whether we will see any precipitation late tonight across the south, with the RAP indicating some QPF in the Brainerd Lakes to Pine City area. A few of the other CAMs are also indicating the potential for some light rain across our southern MN counties. At this point we will keep the forecast dry, but keep a close eye on it. Some light rain may skirt our southern counties on Thursday, but the vast majority of the rain should be south of our CWA. The rest of the area will see conditions range from partly to mostly sunny north to cloudy in the south. Temperatures will be limited a bit due to the cloud cover, especially in the south. .LONG TERM...(Thursday night through Wednesday) Issued at 354 PM CDT Wed Oct 4 2017 A cutoff low over the western United States will slowly open and progress eastward late this week into this weekend. As trough moves into the western Plains on Friday, surface cyclogenesis will take place over Colorado. The poleward transport of moisture ahead of the burgeoning storm system will bring clouds, along with showers and thunderstorms into the Northland. The surface low will continue to strengthen as is moves northeastward into western Iowa by Friday night. A corridor of moderate rainfall is possible from the I-35 corridor east across northwest Wisconsin. Rain and thunderstorms will taper off Saturday afternoon, but due to already saturated soils over the aforementioned areas, the rainfall may lead to areas of flooding. A fast-moving shortwave trough will push through the Northland Sunday night and Monday. A variety of solutions are available today with the GFS bringing a slow and very wet system through the region, while the ECMWF is slower and weaker. The GEM splits these solutions. Stuck with a consensus blend for now due to low confidence. Very cool temperatures aloft in the GFS raise the spectre of light snow mixing into the back side of the Monday system. For now, have followed the trend of the previous shift and removed snow mentions due to low confidence. Will need to keep an eye on these trends over the next few days. Should the GFS solution be close to reality, portions of north-central Minnesota may see their first dusting of snow Monday night. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 640 PM CDT Wed Oct 4 2017 An area of high pressure will move east and south of the region tonight with a trough and shortwave replacing the high with the main impacts just south of the Northland. Clouds will continue to clear this evening from southwest to northeast with additional VFR ceilings moving back into southern areas later tonight and further north on Thursday. Some fog will be possible but we don`t expect widespread fog overnight. Showers will develop over parts of central Minnesota into central and northern Wisconsin. However, we expect KBRD and KHYR will be dry through the period. && .PRELIMINARY POINT TEMPS/POPS... DLH 41 58 40 57 / 0 0 0 30 INL 34 55 32 58 / 0 0 0 10 BRD 40 58 40 57 / 0 0 0 50 HYR 38 58 39 60 / 0 10 10 40 ASX 41 59 40 61 / 0 0 0 20 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...None. MN...Frost Advisory from midnight tonight to 9 AM CDT Thursday for MNZ010>012-018-019. LS...Small Craft Advisory until 4 AM CDT Thursday for LSZ145>147. && $$ UPDATE...Melde SHORT TERM...DAP LONG TERM...Huyck AVIATION...Melde
Area Forecast Discussion
National Weather Service Quad Cities IA IL
1055 PM CDT Wed Oct 4 2017 .UPDATE... Issued at 1053 PM CDT Wed Oct 4 2017 Additional updates have been issued as confidence on dry weather is increasing tomorrow. It looks like the front, which is in central MO, will remain south, and keep the focus of rainfall far away from the area after the wave currently in our south and over central Illinois passes east. Thus, I have taken a wet day of our forecast and reduced it to a chance of showers. This may also allow tomorrow night`s event to miss most of the northern 1/2 of the CWA or more. ERVIN UPDATE Issued at 923 PM CDT Wed Oct 4 2017 Elevated showers are being indicated over the southern 2 tiers of counties as of 9 PM, and scattered showers are now sped up in arrival time to reflect this. AT the moment, activity is so light it`s probably sprinkles, but the wave passing seems to be saturating on target to the recent HRRR runs, and that suggests this activity will continue into the night, along the elevated warm front. ERVIN && .SYNOPSIS... Issued at 330 PM CDT Wed Oct 4 2017 The latest sfc analysis was indicating 1030+ high presssure center slowly settling acrs the upper MO RVR Valley, while the main front was pushing south and east of the local area. Flattened flow/ westerlies continue to adjust from the northern plains through the eastern GRT LKS, with vort max embedded southwesterlies arching up acrs the central Rockies into west central plains. With eventual moisture feed from the south combining with waves electing out of the southwesterlies and along the quasi-stationary front for a potentially significant rain regime into Saturday. && .SHORT TERM...(This Evening through Thursday) ISSUED AT 330 PM CDT Wed Oct 4 2017 Tonight... with the sfc front currently settling acrs central MO and orienting from west-to-east, just a low chance for an isolated elevated shower moving up out of Mo and acrs the southern CWA through midnight. The main overrunning cloud shield will continue from just north of I80 and southward as well, allowing the northern third of the DVN CWA to cool quickly after sunset as winds go light northerly while ridge center slides east toward southwest WI. As a lead vort max shuttles east acrs northern MO and isentropic lift increases along with some return flow signals(such as the MO sfc front retreating back north some into Thu morning), could see an uptick in elevated showers acrs the southern third of the CWA late tonight after midnight into early Thu morning. dry air feed from the north should limit a further north precip progression or keep them mainly as virga up along and north of I-80. Wide range of low temps overnight, with areas of the far north which stay mainly clear the longest cooling into the mid 40s, while the cloudy south stays up in the mid to upper 50s. The MET/NAM MOS even points to some lower 40s in the far north. Thursday...Sharp H8 to H85 MB inversion that forms overnight lasts well into Thu. Continued upper level wave feed out of southwesterlies allows fro more sfc cyclogenesis acrs the central plains as Thu progresses, which acts more upon the boundary for a northward retreat into at least the southern third of the CWA by late Thu afternoon. continued moisture feed, upward vertical velocities and saturation by incoming synoptic scale lift regime, should make for more increased shower coverage and spreading north as the day progresses. Thus the warrant for high afternoon POPs. With the initial dry sub-H8 MB layer to overcome, most areas that get rain will average from around a tenth of an inch, to pushing a half inch of rainfall by 00z Fri. Most areas probably on the lower part of that spectrum. A few models suggest that at least during the afternoon enough elevated MUCAPES to support isolated thunder embedded in the showers/rain especially west of the MS RVR. East to south east sfc winds, clouds and evapo-cooling from the precip to limit many areas to highs in the 60s, maybe the fare south closer to frontal passage and some WAA makes it into the lower 70s. ..12.. .LONG TERM...(Thursday Night through next Wednesday) ISSUED AT 330 PM CDT Wed Oct 4 2017 Wet forecast to begin the period followed by more seasonal weather and another cold front late in the period. Long duration stratiform rain with embedded thunder event will start the period and last through fropa on Saturday across the area. The quiet weather is forecast until Monday into Tuesday when another front moves into the area. 12Z Guidance suggests that the best threat for precip will occur along and south of I80 through Friday morning. Upper level dynamics and LLJ favor precip to our west and south. As the upper level wave shifts to the east, the threat for more widespread rainfall will increase. Friday night, a H85 jet over 50 kts along with PW values near 2 inches will lead to moderate rain across the area. A cold front is forecast to move through on Saturday and will end our chances of rain. Have high confidence rainfall across the southern CWA across our south and west and then area wide Friday into Saturday. Overall confidence in the amount of rain is low. Conditions look favorable for a PRE to develop as the tropical system recurves to our south this weekend. Guidance suggests that this PRE will develop to the east of the area. Questions of what this convection may do to our moisture feed seem reasonable. This will need to be watched through the next 48 hours as guidance on the tropical system track in the Gulf still has considerable spread. This weekend, cooler temps will prevail before a small warm up on Sunday as our next cold front approaches the area. H85 temps at or below 0 are possible into midweek next week. && .AVIATION...(For the 00Z TAFS through 00Z Thursday Evening) ISSUED AT 606 PM CDT Wed Oct 4 2017 Dry low level air will help keep VFR conditions going tonight, through Thursday morning. A warm front will begin to lift north Thursday, with light rain spreading over eastern Iowa during the afternoon. Some isolated thunder is possible, but not well forecast at this time, and only rain is included in TAFs. BRL, as well as southern Iowa, will be close enough to the warm front to see lower MVFR CIGs from late tonight through Thursday, while the northern areas are expecting much higher CIGs through the period. ERVIN && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...Ervin SYNOPSIS...12 SHORT TERM...12 LONG TERM...Gibbs AVIATION...Ervin
Area Forecast Discussion
National Weather Service Grand Rapids MI
1053 PM EDT Wed Oct 4 2017 LATEST UPDATE... Marine .SYNOPSIS... Issued at 325 PM EDT Wed Oct 4 2017 A lull in the rain chances will occur tonight and through the first half of Thursday, but then there will be several chances for rain starting Thursday afternoon and lasting through Saturday. We should dry out for the end of the weekend, with the next chance of rain holding off until Tuesday and Tuesday night. Temperatures are expected the stay mainly above normal in the 70s, with a couple days in the 60s for highs over the next week. && .SHORT TERM...(This evening through Friday night) Issued at 325 PM EDT Wed Oct 4 2017 THe front and showers were exiting the CWA this afternoon. This lull will last until Thursday afternoon/evening, then rain chances return, peaking Friday afternoon and night. After a dry period tonight, the forecast has trended a bit drier for Thursday. The front will sag a bit farther south, with a weak area of high pressure moving across the CWA early Thursday. The return north of the front will be delayed until Thursday night, when it moves from Central IN to the northern part of the state. The front then moves north across Southern Lower Friday. Solid moisture advection follows for Friday night. As the front moves north Thursday night, we should see a few isentropic lift showers break out late afternoon or early evening and these should continue overnight. The best moisture and lift seems to pool toward Central Lower initially, but this merges farther south with the front as the night goes on. The highest chance of showers should occur south of I-96 late Thursday night. We should see a brief lull in the rain as the front moves north of the CWA on Friday, but by late day we begin to see the better moisture advection returning. Along with a coupled jet feature by late day, the rains should see higher coverage, especially south of Highway 46 by late afternoon/early evening. The strongest surge of moisture and lift comes Friday night. We will be in the heart of the moisture advection by this time frame. Surface low pressure will be moving out of IA and into WI. This feature and the upper jet will continue to support healthy lift. Precipitable water values climb to around 1.5 inches by Friday evening and through Friday night. With the ample moisture arriving it is expected that most areas see around a half inch of rain, with much of that coming Friday afternoon and night. .LONG TERM...(Saturday through Wednesday) Issued at 325 PM EDT Wed Oct 4 2017 A low pressure system will move northwest of the region and pull a cold front across the area Saturday into Saturday night. A lack of instability with the front may limit the weather to showers with no lightning. After a break in the weather Sunday into Columbus Day, another low is expected to follow a similar path across the region, bringing precipitation and possibly thunderstorms late on Columbus Day into Tuesday night. Temperatures will be above normal into Tuesday and then cool to a little below normal by Wednesday. Normal highs are in the lower 60s and normal lows are in the lower 40s. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 739 PM EDT Wed Oct 4 2017 Skies should become clear at all TAF sites by 03z and remain so till around 18z Thursday. There is a slight risk of fog toward morning but at this point it seems to questionable to actually put in the TAF forecasts. If there is fog the I-94 taf sites would be the most likely since it rained more significantly there and the clouds did not clear there till after sunset. The low clouds have been slow to clear along the I-94 TAF sites late this afternoon but the latest satellite image loops and RAP and HRRR model data suggest this area of clouds will clear the area by 03z or so. For the most part once the skies nearly do clear (risk of fog AZO, BTL and JXN 09z till 13z) I expect clear skies across the area into late morning Thursday. Then mid level clouds will move in ahead of the next frontal wave heading this way. Skies will become overcast around 5000 ft agl at most if not all taf sites by 21z. No rain is expected until after 00z Friday. && .MARINE... Issued at 1052 PM EDT Wed Oct 4 2017 I have ended the small craft advisory since winds are generally under 15 knots and even at Ludington the significant wave heights have fallen below 3 feet. && .HYDROLOGY... Issued at 325 PM EDT Wed Oct 4 2017 Dry weather will become reestablished over west Michigan tonight in the wake of a cold front and as a brief ridge of high pressure builds over the area. The front will slowly lift back northward through the end of the week, providing increasing chances for rainfall starting Thursday afternoon. The best potential for rain looks to be between Friday afternoon and Saturday evening, when amounts could reach over one-half of an inch. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. LM...None. && $$ SYNOPSIS...JK SHORT TERM...JK LONG TERM...63 AVIATION...WDM HYDROLOGY...HLO MARINE...WDM
Area Forecast Discussion
National Weather Service Houston/Galveston TX
928 PM CDT Wed Oct 4 2017 .DISCUSSION... At 01z, an area of low pressure was over NM with high pressure over the eastern US with a light east wind. At 850 mb, a strong area of high pressure was noted over the eastern US and 850 temps have cooled a bit at LCH with temps down to 15 C. At 300 mb, a sprawling ridge of high pressure was located over South Texas. A few isolated showers linger near the coast but these will become less numerous with time. Not a lot of change to the current forecast with unseasonably warm temps and dry conditions through Sunday. Made some minor tweaks to the grids to match obs but the integrity of the previous forecast is on track. 43 && .PREV DISCUSSION... /ISSUED 626 PM CDT Wed Oct 4 2017/ AVIATION... VFR conditions are expected for most areas tonight and Thursday. Patchy areas of MVFR are possible mainly between 09Z and 13Z at the more rural sites of KCXO and KLBX. Isolated showers could affect KGLS through 02Z and overnight through early morning Wednesday from 06Z to 13Z. 40 PREV DISCUSSION... /ISSUED 354 PM CDT Wed Oct 4 2017/ DISCUSSION... Relatively quiet forecast for several days with little to no potential for precipitation and above normal temperatures. Much of the focus will be on this weekend and early next week as we watch the progress of Tropical Depression 16 and a cold front for early next week. At this time it appears that TD 16 will not track far enough west to cause direct impacts to our area, but there is still a fair amount of spread in the guidance, and it will be important even in Southeast Texas to monitor the latest forecast information from the National Hurricane Center to ensure that expected level of impact continues. Beyond that, we`ll be anticipating the arrival of the next cold front from the northwest, which will increase rain potential on/ahead of the front, but bring cooler and drier air for the mid-week behind it. NEAR TERM [Through Tonight]... Radar is showing a couple weak showers over Jackson County this afternoon, but drier air has pushed in over much of the area from the northeast, and combined with a cap around/below 700 mb in HRRR soundings, that has kept the vertical growth of clouds in check for most today. Can more or less expect this to continue through the rest of the day and into tonight, though some nocturnal activity over the Gulf waters may pop up. SHORT TERM [Thursday Through Friday Night]... Midlevel ridge over Texas should slowly slide and weaken southwest while a northern stream trough digs over the Rockies. Roughly easterly flow will continue far to the north of developing TD 16, aided by high pressure over the Carolinas. Precipitable water is progged essentially unanimously to continue to fall, potentially even below 1 inch, keeping fair weather in the forecast. Though the midlevel ridge is expected to begin weakening, it should impart enough subsidence and fair skies for continued above normal temperatures across the area. LONG TERM [Saturday Through Wednesday]... Changes are afoot for the weekend into early next week. Much of the weekend forecast will be extremely dependent on the precise path of TD 16, even if it does not come close enough to give us direct impacts. Guidance on the left edge of the 16 envelope, like the GFS, crank up PW on the outer edge of the storms`s moisture envelope, and bring back potential for scattered showers and storms over Southeast Texas as we look at a setup with onshore flow and higher moisture. On the flip side, more eastern guidance like the Euro keep us more on the subsident outer edge of the storm, with lower moisture content and flow that is roughly shore parallel. As best I can tell, much of the difference in track for this portion of the forecast hinges on 16`s interaction with a wave/upper trough that crosses the Gulf of Mexico in advance of 16. The GFS is much stronger with this feature, even inducing a bit of a Fujiwara effect between the two lows, which pulls the GFS towards the left side of the envelope. Additionally, it is now nearly 24 hours slower than the Euro with the approach of the northern trough and cold front which also slows steering currents ahead of it, also allowing the storm to drift more towards a Louisiana landfall. While plausible, the Euro`s picture of a weaker leading wave and faster frontal timing seem more realistic, so the forecast leans a bit harder in that direction. This puts the front through the area along with highest rain chances on Tuesday. Cooler and drier air should come in behind the front, knocking temperatures to near or a little below normal. MARINE... East winds 15 to 20 knots will prevail through the night with long period swells of 3 to 7 feet and some wind wave on top. Will carry a SCEC nearshore and SCA 20-60nm. The winds should relax slightly Thursday afternoon. A few showers will prevail tonight with deeper moisture confined to the airmass over the water thanks to the upper ridging over TX/LA/AR. This persistent easterly flow with the long period swell will maintain elevated tide levels and strong rip currents for the Upper Texas Coastal waters through Thursday morning and probably into the evening hours...so have extended the CFW Beach Hazard Statement. Light winds Friday night through Sunday night...followed by a potent cold front (for this time of year) which will boost winds Monday night or more likely Tuesday morning/afternoon into SCA with sustained 20 knot northerlies. Will need to keep an eye on the swell from TD 16 soon to become Nate as this could have some impacts Sunday and Monday with swell. 45 TROPICAL... There is not terribly much to add to the discussion that hasn`t already been mentioned in regards to TD 16. The most important takeaway at this time is to continue to monitor for the latest information from the NHC, and to the latest for us, as to what impacts this will have on our area. These impacts may not be direct storm impacts, but rather indirect, such as issues on Gulf facing beaches due to higher swells from the storm. The precise track of the storm will also strongly influence potential for rain late this weekend. The storm also serves as a reminder that hurricane season does not end until November 30, and it is important to replenish supplies in your hurricane kit. && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 87 69 89 66 89 / 0 0 0 0 0 Houston (IAH) 87 70 89 67 87 / 0 0 0 0 0 Galveston (GLS) 87 78 86 77 86 / 10 10 10 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION until 2 AM CDT Thursday for the following zones: Coastal waters from Freeport to the Matagorda Ship Channel out 20 NM...Coastal waters from High Island to Freeport out 20 NM. Small Craft Advisory until 10 AM CDT Thursday for the following zones: Waters from Freeport to the Matagorda Ship Channel from 20 to 60 NM...Waters from High Island to Freeport from 20 to 60 NM. && $$ Discussion...43
Area Forecast Discussion
National Weather Service Wichita KS
718 PM CDT Wed Oct 4 2017 .UPDATE... Issued at 718 PM CDT Wed Oct 4 2017 Tonight-Thu Morning: Dense fog is spreading SE & 7 PM had spread into Nrn Barton & most of Rice counties. As such, a Dense Fog Advisory has been issued for the 5 northwestern-most counties until 10 AM CDT Thu. && .SHORT TERM...(This evening through Saturday night) Issued at 257 PM CDT Wed Oct 4 2017 A shortwave trough drifting over the central plains has resulted in widespread showers and thunderstorms across much of the forecast area. As the subtle trough axis passes, we should see a period of subsidence in it`s wake. This may persist into much of the evening hours and perhaps much of the night before another round of showers and storms develop toward morning on Thursday with continued mid lvl waa/moisture transport within a very moist pbl with pwats around 2 inches and layer warm cloud depths exceeding 4000 meters. The surface front is still progged to return north on Thursday although the RAP is slower on the return when compared to the GFS and NAM. As the front returns north, there may be a potential for some advection fog with very moist air poised just south of the front. A more significant mid/upper trough will move into the Rockies on Friday. Diffluent mid/upper flow will develop downstream across the central plains where a cold front will arrive late in the day and into the evening hours. This front will become a focus for deep moist convection. Moderate instability and strong deep layer shear will bring the potential for a line of severe storms with damaging winds and some large hail. Heavy rain may aggravate any potential flooding problems. Saturday...a stable post-frontal regime is anticipated as much drier continental air overspreads the area in the wake of the front with seasonable highs in the 70s. There may be a few lingering showers early in the period, however dry weather is expected to prevail by afternoon. .LONG TERM...(Sunday through Wednesday) Issued at 257 PM CDT Wed Oct 4 2017 A mean mid/upper trough is progged across the central Conus as the beginning of the period with a fropa on Monday bringing low probabilities for precipitation and another surge of cooler air. As we move toward the middle of the week, seasonably cool temperatures and drier air is anticipated. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 718 PM CDT Wed Oct 4 2017 Most, if not all, of Central & South-Central KS will be shrouded in LIFR cigs & vsbys throughout the night & until ~15Z Thu. At 00Z, SE KS was in MVFR cig status but deterioration is likely late this eve with LIFR cigs possible ~05Z. Cigs & vsbys should improve to MVFR in all areas ~15Z Thu as lwr-deck flow becomes sly & increases. && .HYDROLOGY... Issued at 257 PM CDT Wed Oct 4 2017 With the potential for additional rounds of heavy rain Thursday night and again along the front on Friday, a flood watch will been issued for much of central KS where some pockets of heavy rain have already occurred. This watch will be in effect from Thursday morning through Friday night. && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 65 78 66 83 / 40 50 50 50 Hutchinson 62 78 66 81 / 50 60 70 70 Newton 62 77 65 80 / 50 60 60 60 ElDorado 65 77 66 82 / 50 50 50 40 Winfield-KWLD 68 78 67 83 / 40 50 30 30 Russell 58 78 63 74 / 50 50 90 70 Great Bend 59 78 64 75 / 50 50 80 60 Salina 61 79 67 78 / 70 80 90 70 McPherson 61 78 66 79 / 50 60 80 70 Coffeyville 67 78 66 83 / 50 40 20 10 Chanute 67 77 66 82 / 50 60 30 30 Iola 67 77 66 82 / 60 60 40 30 Parsons-KPPF 68 78 66 82 / 50 50 20 20 && .ICT WATCHES/WARNINGS/ADVISORIES... Flood Watch from 7 AM CDT Thursday through Saturday morning for KSZ032-033-047>050. Dense Fog Advisory until 10 AM CDT Thursday for KSZ032-033-047- 048-050. && $$ UPDATE...EPS SHORT TERM...MWM LONG TERM...MWM AVIATION...EPS HYDROLOGY...MWM
Area Forecast Discussion
National Weather Service Lincoln IL
854 PM CDT Wed Oct 4 2017 .UPDATE... Issued at 854 PM CDT Wed Oct 4 2017 Showers are steadily advancing into central Illinois from the SW, as a shortwave progresses to the east along the stalling out cold front. Soundings show limited instability available for this wave, and no lightning is being reported near our area, not even cloud flashes. The showers are arriving slightly faster than the high resolution models indicated a couple hours ago, and we have updated the PoPs/Weather to reflect the expected short term trends. The precip shield should advance eastward toward Indiana the rest of the night, with northern areas seeing less precip amounts, but still light rain/drizzle are poised to affect areas north of I-74. HRRR is showing additional shower development later tonight farther north toward Peoria, which will push toward Bloomington after sunrise. Low temps will be held up by clouds and precip, with mid 50s north and mid 60s south. Only minor changes needed this evening to hourly temps/dewpoints. The latest forecast info is already available. && .SHORT TERM...(This evening through Thursday) ISSUED AT 301 PM CDT Wed Oct 4 2017 A relative lull in precipitation chances will take place tonight into early Thursday morning with a cold front stalled out between I- 72 and I-70, then precipitation will increase Thursday as southerly flow across the area pushes the front northward as a warm front. Expecting enough instability for isolated thunderstorms by Thursday afternoon. With the frontal boundary stalled in the area tonight we should see patchy fog forming in the general vicinity, which is currently depicted by several models. Lows tonight should range from 55 to 60 north of I-74 to the mid 60s south of I-70. Areas between I-72 and I-70 may see high temperatures increase a few degrees to around 80 due to the northward migration of the front through the day, but otherwise temperatures will be roughly the same as Wednesday with highs from the lower and mid 70s north of I-72 and the lower 80s south of I-70. .LONG TERM...(Thursday night through Wednesday) ISSUED AT 301 PM CDT Wed Oct 4 2017 Thursday night, precipitation rates should increase especially west of the Illinois River as a low level jet strengthens from the southern Plains into the mid-Mississippi Valley region. This area of precipitation should shift eastward Friday especially through areas north of I-72 and have likely to categorical PoPs in this area. A strong upper level wave arrives Saturday bringing another focused period of showers and thunderstorms. Precipitation totals from tonight into Saturday night still look to potentially exceed 2 inches northwest of the Illinois River, but decrease down to around 1 inch along I-72 and less than 1/2 inch along and south of I-70. Warmer than normal temperatures look to prevail through much of the next week before a cooler air mass is indicated starting around the middle of next week. Until then, models are very inconsistent handling a potential trough for early next week. Have a chance of precipitation to account for this potential system, but uncertainty in this time period remains high. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 659 PM CDT Wed Oct 4 2017 The stalled frontal boundary, roughly between I-70 and I-72, will keep winds light and variable overnight. A wave of energy advancing along the front this evening will cause showers to expand in coverage from SW to NE. High resolution guidance and forecast soundings support IFR or LIFR clouds for our southern terminals of SPI and DEC, closer to the front. VFR conditions are expected for the northern terminals of PIA, BMI, and possibly CMI later this evening as mixing increases with the arrival of showers. MVFR fog appears poised to develop, after a day of light rain/drizzle across central Illinois, and little change in airmass overnight. The fog could drop to IFR later tonight, but have not included those conditions yet. Some improvement to VFR is projected for tomorrow afternoon, with showers and even a few thunderstorms possible. Confidence in thunder is low, with marginally unstable conditions expected. Winds will vary widely from north to south across our area, due to the location of the stalled front. Wind speeds should remain light throughout the next 24 hours. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Shimon SHORT TERM...37 LONG TERM...37 AVIATION...Shimon
Area Forecast Discussion
National Weather Service Indianapolis IN
1141 PM EDT Wed Oct 4 2017 .UPDATE... The AVIATION Section has been updated below. && .SYNOPSIS... Issued at 334 PM EDT Wed Oct 4 2017 A frontal boundary will settle into the region and stall overnight, before returning back northward as a warm front later in the week as the accompanying cold front pushes toward the area. This will bring multiple opportunities for showers and perhaps a rumble of thunder to the area at times through the weekend and into early next week. && .NEAR TERM /Overnight/... Issued at 942 PM EDT Wed Oct 4 2017 Surface analysis late this evening shows low pressure near St. Louis. Water vapor shows a short wave associated with this feature along with abundant cloud cover ahead of the low. Radar mosaics show showers over western Illinois and eastern Missouri...pushing eastward. Models suggest the eastward propagation of the rain showers across Central Indiana overnight. Forecast soundings and Time heights also show deep saturation arriving by 10Z-12Z. Dew points across the area were in the middle 60s...plenty of moisture available for early October. Thus have trended pops higher overnight as the short wave and associated precip shield should reach Central Indiana for the morning rush hours. Given the expected increase in cloud cover trended overnight low at or above the forecast builder blend...expected across the far east where some mostly clear skies allowed temperatures to fall rather quickly. && .SHORT TERM /Thursday through Saturday/... Issued at 334 PM EDT Wed Oct 4 2017 Will carry chances again tomorrow as late night impulse continues to impact the area into the morning hours. Chances will again be lesser later in the day but with some potential for warming have added isolated thunder to the afternoon hours. Thursday night and Friday focus will be more towards the north nearest the boundary and another upper level wave with a strong gradient of pops over the area. Convective indices suggest our next reasonable chance for a few rumbles of thunder will come Saturday afternoon as the cold front approaches. Consensus temperatures appeared reasonable throughout. Should see highs climb a bit back into the 80s by Saturday as we get into the warm sector. Lows through the period will generally remain in the lower 60s as moist air remains in place across the area. && .LONG TERM /Discussion for Saturday night through Wednesday/... Issued at 235 PM EDT Wed Oct 4 2017 Much of the extended period remain unsettled with periods of showers and storms until a strong cold front arrives Wednesday. Model differences are not huge and a blend is a fair compromise. Temperatures will remain above normal until much cooler and below normal readings arrive Wednesday. The period starts with a surface pressure trough settling southeast across the area with showers and storms still possible across our southern counties Saturday night. Sunday into Monday, a bit of model variance here but all trend to pulling tropical moisture a bit further north into the Ohio Valley. Rain chances still appear best in our southern counties but chances up to I-70 corridor not out of the question. This wave exits the area Monday night. Tuesday and Wednesday...models agree in bringing full latitude trough across nations midsection with fairly decent shower and storm chances here. Model differences are in how much, if any, a second surge of tropical moisture gets drawn into our area ahead of the approaching trough. End result of differences likely to translate into total precipitation amounts with this final surge of wet weather before strong drying and cool temperatures settle in. With a continuation of weak upper ridging or zonal flow for our area, no real surge of cool weather is expected before the large trough arrival Wednesday. Thus blend of well above normal max and min temperatures through Tuesday looks good followed by below normal Wednesday. && .AVIATION /Discussion for the 050600Z Tafs/... Issued at 1141 PM EDT Wed Oct 4 2017 VFR Conditions are expected to deteriorate to MVFR overnight. Showers and lower cigs associated with Low Pressure over Missouri will push east to central Indiana in the next 3-6 hours. Forecast soundings and Time height sections continue to show a saturated column near 12Z with continuing through the morning hours as the low and associated short wave pass across Indiana. HRRR is also in agreement for showers across the area near 12Z. Best lift and moisture is lost after 18Z and will expect some improvement in conditions at that time. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...Nield NEAR TERM...PUMA SHORT TERM...Nield LONG TERM...Tucek AVIATION...JP