Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/17/22


Area Forecast Discussion
National Weather Service Grand Rapids MI
941 PM EST Wed Nov 16 2022 LATEST UPDATE... Update .UPDATE... Issued at 925 PM EST Wed Nov 16 2022 Low level troughing continues to focus the main bands of snow closer to Lake MI especially towards Van Buren County. Earlier the heavier snow showers around Mt Pleasant generated some hazardous travel for a short period of time. Those impactful snow showers moved off to the east of that area. Surface temperatures have fallen into the 30 to 32 degree range so some icing may develop overnight especially for bridges and overpasses. The 00z GRB sounding captured the steeper low level lapse rates which helped to generated the stronger snow showers. This setup does not change much overnight. Impressive lake effect setup for Thu especially in the afternoon as deep cyclonic flow and moisture coupled with cold air advection supports increasing bands of lake effect snow. Impacts will likely expand during that time. Thus we will not make any changes to the headlines. && .DISCUSSION...(This evening through next Wednesday) Issued at 316 PM EST Wed Nov 16 2022 Forecast concerns deal with the approaching snowy period and subsequent headlines needed to describe the hazard and impacts. Essentially, the Winter Storm Watch was upgraded to a Winter Storm Warning and a Winter Weather Advisory was issued everywhere else. The lake shore will see those headlines begin this evening for reasons noted below. The short range models have a pretty good handle on the evolving weather pattern. We`re following the HRRR during the next 24-36 hrs. Regional radar shows lake effect snow developing over the northern part of Lake Michigan and this snow has a connection to Lake Superior. These snow showers will continue south tonight and the HRRR shows them moving a bit inland during the evening and overnight. We`re likely to see visibilities fall to 3 to 5 miles west of US-131 and roads will become slick. Although road temperatures are in the lower 40s, once air temperatures fall below freezing, we`ll see some icy spots develop. A strong short wave rotating around the deep upper low will create substantial boundary layer lift beginning tomorrow. H8 temps fall from -8c to -12c by 18z, -14z by 06z Friday and -16z by the weekend. The first short wave moves in Thursday and the second potent wave moves through Saturday. Thus, we`re looking at a prolonged period of lake effect (mixed with synoptic) snow. Boundary layer winds will be from a westerly direction which favors areas bounded by I-94/I-96. We have the Winter Storm Warning in this area. Total snow through Friday night could be in the one foot range with areas in the northeast cwa seeing only a couple of inches. Bufkit omega profiles show a brief spike in upward motion through the DGZ around 06z tonight. Other bullseyes were noted but generally below the DGZ until Saturday afternoon, when the omega bullseye is square in the DGZ. This also coincides with the next push of arctic air. The upper trough finally moves out Sunday and h8 temps quickly rise to -6c by 00z Monday. This will spell the end of the lake effect snow with dry weather expected early next week. Saturday and Sunday will be the warmest days as highs will only be in the mid 20s. Once the trough moves east, highs will climb back toward 40 by the middle of next week. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 642 PM EST Wed Nov 16 2022 Lake effect snow showers...some of them producing sub IFR conditions were tracking through portions of Southwest Lower MI to start the period. In general the inland TAF sites will see the activity persist for a few hours this evening then diminish for a period later this evening into tonight. However that will not last as the southwest flow picks up and colder air advects in late tonight into Thursday morning. This will strengthen and expand the snow activity...which will likely persist through much of the remainder of the day. IFR and lower impacts are predicted through the day on Wednesday. Being lake effect...conditions will be highly variable and will change rather quickly at times. && .MARINE... Issued at 316 PM EST Wed Nov 16 2022 No changes to the marine headlines. Wind will be mainly northwesterly tonight and keep the larger waves farther out in the lake. However, when winds become more westerly Thursday, waves will increase in the nearshore waters. Colder air plowing into the region will cause waves to rise quite a bit and so our current headlines extend through Sunday and may have to eventually be extended into next week. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Winter Weather Advisory until 7 AM EST Saturday for MIZ037-043- 050. Winter Weather Advisory from 7 AM Thursday to 7 AM EST Saturday for MIZ038>040-044>046-051-052-059-067-074. Winter Storm Warning until 7 AM EST Saturday for MIZ056-064-071. Winter Storm Warning from 7 AM Thursday to 7 AM EST Saturday for MIZ057-058-065-066-072-073. LM...Small Craft Advisory until 7 PM EST Sunday for LMZ844>849. && $$ UPDATE...MJS DISCUSSION...04 AVIATION...MJS MARINE...04
Area Forecast Discussion...UPDATED
National Weather Service Gray ME
933 PM EST Wed Nov 16 2022 .SYNOPSIS... Low pressure exits to the east tonight. Upslope snow showers develop in the mountains and continue into Thursday, but the rest of the area will be dry with partly to mostly sunny conditions Thursday. Several rounds of snow showers will be chances for snow showers in the mountains are possible through the weekend while southern areas remain mostly dry and temperatures running slightly below normal. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Update...Temps and dewpoints have been slow to fall tonight as low level inversion keeps mechanical mixing to a minimum. Eventually CAA will win out...but I have delayed the concerted cooling until very late tonight/early Thu. Otherwise no significant changes to the forecast. Previous discussion...The latest RAP13 surface analysis and surface observations indicate that the center of low pressure is now located just offshore of the Maine coastline at this hour. Radar shows the steadiest of the precipitation has now moved northeast of the region with just some lingering light rain/drizzle south of the mountains and light snow further to the north. Current temperatures range from near 50 degrees along the NH Seacoast to the lower 30s in interior sections of western ME and NH. Low pressure will continue to pull away from New England tonight before moving over the Bay of Fundy by early Thursday morning. In doing so it will begin to pull down drier air from the north, bringing an end to precipitation south of the mountains by late this evening along with gradually clearing skies. Given the plethora of moisture on area roadways and walkways, locally icy conditions on untreated surfaces are possible overnight through early Thursday morning as temperatures bottom out into the 20s. As a result, drivers should be prepared for areas of ice and use caution if traveling. Across the mountains and point north, increasing CAA from the north will allow for upslope snow showers to develop with light accumulations possible. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... Clouds will gradually increase some during the day on Thursday as a shortwave trough swings through northern New England. This wave will provide some lift and given some sunshine and surface warming, weak low-level CAPE and increasing low to mid-level lapse rates will provide an opportunity for a few scattered snow showers and perhaps even a snow squall. The latest NAM continues to show snow squall parameters in the 3-5 range developing during the afternoon, mainly across western NH. The latest few CAM runs including the HRRR show some heavy snow showers/squalls approaching the CT River Valley between 12-2 pm before dissipating during the late afternoon/early evening. This will therefore need to be watched given the potential localized impacts to the evening commute. Across the north and mountains more persistent upslope snow showers/clouds will prevail with additional light snow accumulation. High temperatures will range from the lower 30s across the north and mountains to the lower 40s in southern areas. It will feel colder though as northwest winds will frequently gust between 20-25 mph. Winds will subside on Thursday evening as we lose daytime heating and this combined mostly clear skies south of the mountains will allow lows to fall into the lower 20s. Across the north and mountains, more in the way of cloud cover will linger along with scattered snow showers. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Current, fairly stable, +PNA pattern at 500 MB starts to break down after this weekend, and become less amplified. Through the weekend we should stay under the influence of general weak cyclonic flow, with seasonably cool temps and perhaps a few threats of SHSNRA, mostly in the mtns, but nothing in the way of significant precip. Flow becomes less amplified and more zonal early to middle of next week, with generally dry conds and a possible warming trend. Some signs late next week for possible storm system, but confidence this far out is low. Friday will be another cool and breezy day with a wave passing to our N and a threat of SHSN in the mtns late Friday and Friday night, followed by a dry and mainly sunny day Sat. A broad trough quickly moves through on Sunday and could see more clouds and a threat of SHRASN again. Highs through the weekend will generally range from the low 30s in the N to the low 40s in the S. Monday and Tuesday look mainly dry, sunny and warmer with highs in the upper 30s to mid 40s. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... Short Term...IFR/LIFR restrictions will gradually improve from south to north this evening with any remaining RA/SN ending except across northern TAF sites including KHIE. Mostly VFR is then expected tonight through Thursday night except at KHIE where continued MVFR restrictions are likely due to SHSN and lower ceilings. Northwest winds will gust up to between 20-25 kts across all TAF sites during the day on Thursday. Long Term...Mainly VFR Friday through the weekend. Only exception is KHIE, which could see periods of MVFR cigs and SHSN. && .MARINE... Short Term...Winds will become offshore tonight through Thursday night with frequent gusts of 25-30 kts and a few gusts up to 35 kts possible. Also, seas will remain elevated at 4-7 ft. Long Term...SCA winds are likely to persist Friday into Sat, before diminishing somewhat Sunday and Monday. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory until 7 AM EST Friday for ANZ150>154. && $$ NEAR TERM...Legro
Area Forecast Discussion
National Weather Service Louisville KY
956 PM EST Wed Nov 16 2022 .Forecast Update... Issued at 950 PM EST Wed Nov 16 2022 Shortwave embedded in the upper-level trough continues to work across the Ohio Valley this evening. With steep low-level lapse rates and help from a LLJ of 25-30kts we`ve seen snow showers over the northern half of our CWA. Current observation and KLVX WSR-88D radar imagery has a swath of light to moderate snow showers moving through the Bluegrass with the heaviest bursts of snow located across Washington, Mercer, Boyle and Jessamine counties northward towards Cincinnati, OH. These snow showers should continue to quickly move off to the east and exit out of the area between 04- 05z. Most locations have seen a quick dusting on cars and elevated surfaces. Snow will taper off but low stratus behind the trough located over central/northern IL will move in over southern IN/northern KY. Because of the clouds decided to increase overnight lows in southern IN/norther KY up a few degrees. Issued at 550 PM EST Wed Nov 16 2022 Monitoring area WSR-88D returns, observations and traffic cameras from both Indiana and Kentucky decided to up our PoPs to around 20 percent for some scattered light snow and flurries through this evening. Impacts remain minimal but a brief burst of snow in an isolated band, especially across southern IN and norther KY along the Ohio River is possible. SPC Meso-analysis shows a 25kt 850mb LLJ over northern KY and southern IN this evening with the RAP suggesting we could see areas up to 30kts adding to slight enhance lift. Model soundings and cloud tops support areas of saturation in the DGZ along with some steep low-level lapse rates where we had sunshine close to 6 C/km. While there is support for light snow we have dry a dry layer below 3K ft keep most of the snow showers light to just flurries. Temperatures will also remain slightly above to just near freezing during the time of highest PoPs and ground temperatures as well as road temperatures remain above freezing. && .Short Term...(This evening through Thursday) Issued at 315 PM EST Wed Nov 16 2022 After some sunshine filtering through this afternoon as drier air set in, we will see low level clouds move over central KY from the west. Breezy westerly winds will eventually die down by this evening as daytime mixing diminishes, but west winds should remain between 5- 10 mph overnight. We are currently located underneath broad upper troughing, with another subtle shortwave expected to pass through the Ohio Valley tonight. Several hi-res CAMs have been hinting at a quick moving wave of wintry precip this evening as a vort lobe swings through. Model soundings show a shallow layer of moisture tapping into the DGZ this evening, with steep low level lapse rates but a decent dry layer at the sfc will likely limit most precip chances. No accumulations are currently expected, though should we be able to tap into more moisture, the steep lapse rates will result in brief snow showers that could result in very light accumulations. Not entirely confident on this, but given the broad ascent over the area it is possible. Will blend hi-res guidance to highlight an area of sprinkles/flurries for a short period mainly across central KY tonight. Lows for tonight will drop down into the low to mid 20s. For tomorrow, the upper flow flattens into a more zonal pattern. A dry forecast is expected for tomorrow, with the greatest cloud coverage expected along and north of I-64. With this in mind, cooler high temps are expected across southern IN, with mid 30s possible. Temps closer to 40 are expected to the south across Kentucky. .Long Term...(Thursday night through Wednesday) Issued at 300 PM EST Wed Nov 16 2022 Thursday Night - Sunday... A cold front will bring a reinforcing shot of cold air to the region for the weekend. Expect unseasonably cold temps with highs in the 30s to low 40s and low temperatures in the teens and low 20s Fri- Sat-Sun. In addition to the cold air, the front could also bring a few flurries/sprinkles to the area late Thu night into Fri morning but feel the majority of the model soundings are too dry to mention any precipitation in the forecast attm. Sat-Sun look dry with sfc high pressure moving in from the west. Monday - Wednesday... By Monday, return flow should commence as the high pressure moves eastward out of our area. This will result in a warming trend through mid week. High temps will moderate into the 40s for Mon with 50s for highs by Tue/Wed. 12Z long range models indicate an upper level shortwave could bring a slight chance for precip to the area Tues. However, the best chance for the return of rain should come Wed-Thu ahead of a potent low pressure system over the central U.S. && .Aviation...(00Z TAF Issuance) Issued at 640 PM EST Wed Nov 16 2022 Local WSR-88D, observations as well as traffic cameras across southern IN and northern KY have shown pockets of light snow and flurries this evening but with dry air below 3000ft, it has been a challenge for any of this precipitation to reach the ground. Given this trend and upstream reports, decided to go with vicinity showers for snow and flurries through the first part of the forecast cycle. Winds were also breezy out of the west up to 10kts. Winds will die down some overnight and our mid-level cloud deck should break up a bit later tonight into early tomorrow morning with mostly clear skies. Models suggest a slight increase in clouds just before dawn tomorrow morning with CIG between 2500-3000 which would put them into MVFR categories. Confidence right now is low on this so went with the mention of SCT clouds at this level. The overall thought for this TAF cycle is VFR conditions with moderate to high confidence. Will have to monitor through the first few hours for the forecast for possible light snow showers, then tomorrow morning for more BKN/OVC MVFR CIG. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Update...BTN Short Term...CJP Long Term...AMS Aviation...BTN
Area Forecast Discussion
National Weather Service Miami FL
702 PM EST Wed Nov 16 2022 ...New UPDATE... .UPDATE... Issued at 657 PM EST Wed Nov 16 2022 As is often the case, the cold front is taking it`s time crossing South Florida this evening. It will continue it`s slow NW to SE overnight likely not fully clearing SE FL until the early morning hours tomorrow. Latest HRRR run still shows the potential for some isolated showers along the east coast metro this evening, but most of the activity should remain over the Atlantic waters. Made some minor tweaks to wind and sky cover based on the latest obs, but overall the forecast remains on track. && .SHORT TERM... (Rest of today through Thursday) Issued at 222 PM EST Wed Nov 16 2022 Originating in the FL Panhandle this morning, a cold front is making progress across the Peninsula today. As the front continues south- southeastward, it is expected to move through South Florida tonight. With the diurnal heating and sea breezes, there will be an opportunity for light showers and isolated thunderstorms in the late afternoon and evenings across the southeast. 12Z soundings confirm the opportunity for weak to moderate convection as previously forecasted - with CAPE values reaching 1500 J/kg and lapse rates supporting a conditionally unstable atmosphere. PWATs are not showing much moisture, with model indication the best chance for showers will be over the Atlantic Ocean. Tomorrow will be drier with an uptick in breezy wind speeds. There is a chance for light showers, but most will remain over the Gulf Stream waters. Conditions will be mostly cloudy with winds gusting up to 20KT especially along the east coast. Afternoon highs are expected to be the last day of above normal temperatures as they reach the mid-to-upper 80s across most of south Florida. There may be some interior locations pushing 90 degrees. There will be numerous daily records in jeopardy today! Following the warm day, the cold front will usher much cooler air into the region with overnight lows cooling to near seasonal temperatures. Lows in the interior will be in the low to mid 60s with the eastern metro areas falling into the upper 60s. There will be quite a spread in temperatures tomorrow. Highs near Lake Okeechobee will struggle to reach 70 while Broward/Miami- Dade/Monroe Counties will have no problem reaching upper 70s to 80.&& .LONG TERM... (Thursday night through next Tuesday) Issued at 222 PM EST Wed Nov 16 2022 The front will stall just to our south over the Straits of Florida on Friday and Saturday, as a CONUS longwave trough remains in place, and the mid/upper level wind flow parallels the frontal boundary. As a result, clouds and scattered showers look to linger over east coast metro areas on Friday, then over most of the area on Saturday as low-level NE winds transport Atlantic moisture over the southern peninsula in the vicinity of the boundary. Models for the past couple of days have been hinting at perturbations in the mid/upper level SW flow moving from the Gulf of Mexico across South Florida late this weekend, overriding the moist NE-E winds near the front. This would result in the second half of the weekend being quite gloomy and wet. PoPs for Sunday and Monday will lean slightly on the higher side, ranging from 30% around the Gulf Coast to 50% on the East Coast. Locally heavy rainfall is a possibility with this setup. As we move into the early and middle part of Thanksgiving week, models continue to show the front draped across the area with plenty of moisture in the low and mid-levels riding over the front. A continuation of the rather wet pattern therefore looks to be in store. Temperatures on Friday morning are forecast to drop into the 50s around Lake Okeechobee and most of SW Florida, with 60s elsewhere. This will be the coolest morning as clouds and moisture increase over the weekend and keep lows in the 60s to around 70F. Highs will be mainly in the 70s through the long term period, held down primarily by clouds and precipitation as we get later into the weekend and early next week. && .LONG TERM... (Thursday night through next Tuesday) Issued at 222 PM EST Wed Nov 16 2022 The front will stall just to our south over the Straits of Florida on Friday and Saturday, as a CONUS longwave trough remains in place, and the mid/upper level wind flow parallels the frontal boundary. As a result, clouds and scattered showers look to linger over east coast metro areas on Friday, then over most of the area on Saturday as low-level NE winds transport Atlantic moisture over the southern peninsula in the vicinity of the boundary. Models for the past couple of days have been hinting at perturbations in the mid/upper level SW flow moving from the Gulf of Mexico across South Florida late this weekend, overriding the moist NE-E winds near the front. This would result in the second half of the weekend being quite gloomy and wet. PoPs for Sunday and Monday will lean slightly on the higher side, ranging from 30% around the Gulf Coast to 50% on the East Coast. Locally heavy rainfall is a possibility with this setup. As we move into the early and middle part of Thanksgiving week, models continue to show the front draped across the area with plenty of moisture in the low and mid-levels riding over the front. A continuation of the rather wet pattern therefore looks to be in store. Temperatures on Friday morning are forecast to drop into the 50s around Lake Okeechobee and most of SW Florida, with 60s elsewhere. This will be the coolest morning as clouds and moisture increase over the weekend and keep lows in the 60s to around 70F. Highs will be mainly in the 70s through the long term period, held down primarily by clouds and precipitation as we get later into the weekend and early next week. && .AVIATION... (00Z TAFS) Issued at 610 PM EST Wed Nov 16 2022 VFR through the 00Z TAF period. A cold front is crossing the area this evening, with winds behind the front initially becoming NW overnight and then N/NE on Thursday, with speeds of 10-15 kts by the afternoon. An isolated shower can`t be ruled out over the east coast metro overnight into early Thursday, but chances are too low for mention at any specific terminal. && .MARINE... Issued at 222 PM EST Wed Nov 16 2022 North-northeast winds will increase tonight after the frontal passage. Small craft caution conditions are possible for most of the forecast period as winds are expected to be in the 15-20 knot range and seas 4-6 ft on Thursday and Friday. The winds are expected to gradually become easterly on Saturday and Sunday and remain in the 15-20 knot range with seas 4-6 ft. Showers over the Atlantic waters Thursday and Friday will increase in coverage over all waters as we head into the upcoming weekend. A few thunderstorms may also develop over the Atlantic waters by the weekend. && .BEACHES... Issued at 222 PM EST Wed Nov 16 2022 Lingering northerly swell will keep a moderate risk of rip currents at the beaches of Palm Beach County today. The rip current risk should begin to increase at all Atlantic beaches Thursday and continue through the upcoming weekend due to stronger northeast-east winds. && .PRELIMINARY POINT TEMPS/POPS... Miami 72 83 67 80 / 10 10 20 20 West Kendall 69 83 65 80 / 10 10 20 20 Opa-Locka 69 82 66 79 / 10 10 20 20 Homestead 69 83 66 79 / 10 10 30 20 Fort Lauderdale 71 81 67 79 / 10 10 20 20 N Ft Lauderdale 71 80 67 78 / 20 10 20 20 Pembroke Pines 69 81 66 79 / 10 10 20 20 West Palm Beach 69 78 66 78 / 20 10 20 20 Boca Raton 70 80 66 79 / 20 10 20 20 Naples 64 77 59 75 / 10 0 0 0 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. GM...None. && $$ SHORT TERM...Simmons LONG TERM....Culver AVIATION...CMF
Area Forecast Discussion
National Weather Service Nashville TN
930 PM CST Wed Nov 16 2022 ...New UPDATE... .UPDATE... Issued at 914 PM CST Wed Nov 16 2022 Only minor changes needed to the forecast this evening as temperatures have remained a few degrees warmer in portions of Middle TN where clouds are moving overhead. Adjusted hourly temperatures to reflect this, but left overnight lows alone as temps should fall quickly once clouds clear. Any chance for flurries looks limited to the upper Cumberland Plateau before midnight, but ground temperatures remain warm enough to keep any accumulation worries at a minimum. && .SHORT TERM... (This afternoon through Friday Night) Issued at 213 PM CST Wed Nov 16 2022 Snow flurries are being reported across portions of central and southern MO this afternoon. The GFS still brings a narrow slug of 850mb moisture across the mid state this evening. This is further supported by the Hrrr and namnst as well. Remainder of models lean toward a totally dry scenario. However, Middle TN is within the brief favorable pva window with sub 800 ft freezing levels in alignment. So I will go ahead and put just a slight chance of flurries across our north this evening. sat imagery does depict the lower cloudiness moving this way. At any rate, nothing to be alarmed about. Moving on, thermal trough amplification will relax but heights will remain quite low. 850 mb temps of -4C to -6C will prevail throughout the short term period. Reinforcement of the cold air will occur Thursday night as, what looks to be, a dry cold front moves through. 12Z w-e surface ridging looks strongest Saturday morning but there could be a few added clouds. Thus, the next 3 overnights look rather cold with lower to mid 20s for lows. && .LONG TERM... (Saturday through next Wednesday) Issued at 213 PM CST Wed Nov 16 2022 In the extended forecast, another dry cold front expected Saturday afternoon. The surface high will reach our area by Sunday sunrise. At that time, the upper flow will become more zonal with 850 mb temps finally going north of 0C. This will equate to dry and warmer conditions. Upper pattern attempts to split with some southern energy toward mid week. Thats the next chance of substantial rainfall but that might hold off until the 7-10 day period. Again, temperatures for the beginning of the extended will be cold through the weekend. Then a marked warming trend into mid week. Maybe, just maybe, we could see lower to mid 60s by Wednesday. && .AVIATION... (00Z TAFS) Issued at 526 PM CST Wed Nov 16 2022 VFR conditions expected through the TAF period as high pressure builds overhead. A few light snow flurries may be possible along the TN/KY state line through 06Z. The flurries will be so light have not included in any of the TAF sites...however CKV would be the only one in question. Winds will be westerly 10 kts or less and possible becoming a bit gusty after 18Z. && .PRELIMINARY POINT TEMPS/POPS... Nashville 25 44 25 43 / 0 0 0 0 Clarksville 23 43 25 42 / 10 0 0 0 Crossville 21 38 22 41 / 0 0 0 0 Columbia 23 45 24 45 / 0 0 0 0 Cookeville 22 40 23 41 / 0 0 0 0 Jamestown 21 37 23 39 / 0 0 0 0 Lawrenceburg 24 45 24 45 / 0 0 0 0 Murfreesboro 22 45 21 44 / 0 0 0 0 Waverly 22 43 24 42 / 0 0 0 0 && .OHX WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE.......Whitehead SHORT TERM...21 LONG TERM....21 AVIATION.....12