Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/02/22


Area Forecast Discussion
National Weather Service Quad Cities IA IL
655 PM CDT Fri Apr 1 2022 ...00Z AVIATION UPDATE... .SYNOPSIS... Issued at 252 PM CDT Fri Apr 1 2022 Surface high pressure is in place along the Mississippi River this afternoon while on water vapor tonight`s shortwave is evident moving into central South Dakota and Nebraska. Diurnally driven cumulus has developed across the area with temperatures generally in the lower to mid 40s. Dewpoints ranged from mid 20s to lower 30s across the area. && .SHORT TERM...(This Evening through Saturday) ISSUED AT 252 PM CDT Fri Apr 1 2022 1. A fast moving storm system will bring accumulating snow to part of the area late tonight into Saturday morning. 2. A Winter Weather Advisory has been issues for Iowa Counties along and north of Highway 30 plus Jo Davies County in Illinois. 2 to 4 inches of snow is possible in the advisory area with a slushy 1 to 2 inches of snow on area roadways. Discussion: The main forecast concern is precipitation type and timing. There are slight differences between the models in the timing and placement of this shortwave. Models show the 500 mb ridge axis along the Mississippi River by 00 UTC this evening with a 500 MB trough spreading into central Nebraska. The latest runs of the ECWMF and GFS continue to be about 50 to 100 miles east of the NAM and Canadian. The best accumulations will be prior to sunrise. This is leading to slight timing differences between the models. The ECWMF and GFS continue to time the best lift across eastern Iowa in the 9 to 12 UTC timeframe while the NAM and Canadian are about 3 hours hours slower. Additionally, the HRRR and NAMNest show a secondary area of intense precipitation across the I-80 corridor. Low temperatures across all but the Highway 20 corridor will be in the mid 30s where lows will be in the lower 30s. As the atmosphere saturates from the top down, precipitation falling into the layer will result in the lower part of the column dropping below freezing and precipitation changing over to all snow, mainly along and north of Highway 30. This will lead to accumulations of 2 to 4 inches. Rates overnight may approach 1 inch per hour during the peak. Expecting a mix to redevelop after sunrise as the atmosphere slowly warms to do insolation. South of Interstate 80, precipitation is expect to fall as all rain. Precipitation will come to an end from west to east Saturday afternoon. As the cold front sweeps across the area Saturday expect northwest winds of 10 to 25 MPH to develop behind the front and continue through the rest of the day. High temperatures on Saturday will range from the lower 40s in northwest Illinois to the mid 50s in far northeast Missouri. .LONG TERM...(Saturday Night through Friday) ISSUED AT 252 PM CDT Fri Apr 1 2022 Key Messages: 1. Active pattern through the long term with series of clippers. 2. All precip looks to be rain. Discussion: Active flow regime expected through next week. Parade of clippers will bring chances for precip and wind throughout. The first clipper is expected to move in for Sunday. Into next week, a clipper midweek is expected to move through the area as an closed upper level low takes over for the rest of the work week, leading to precipitation through that period. Sunday, precipitation will encounter dry low levels. Rain will be slow to overspread the area until the main wave approaches the area. While there are chances for rain on Sunday afternoon, the bulk of the precip should fall after 00z Monday and into the overnight. Current rainfall forecast of a tenth to half an inch of rain is expected. This will also help with our ongoing drought across the area. Later in the week, a more complex momentum field is found across the area as a wave followed by closed low is expected to affect the region. This will likely lead to extended periods of cloud cover. Rain looks likely with the front on Wednesday then again later Thursday with the wrap around. Thermal fields suggest all rain with this event midweek. That said, some mixing in of snow during the night time is possible. Afternoon temps will melt any snow that does fall at night. Depending on the guidance, this system could also bring us half an inch to 1.5 inches of needed rain as well. && .AVIATION...(For the 00Z TAFS through 00Z Saturday Evening) ISSUED AT 645 PM CDT Fri Apr 1 2022 VFR conditions will be seen through 06z-09z. Thereafter, conditions will lower into MVFR with some IFR as a low pressure system passes, accompanied by rain/snow primarily until 18z. Rain is expected at BRL mostly for a few hour period. Rain is initially expected at MLI, but then is likely to mix with or possibly even change to a brief period of snow before ending. CID/DBQ will see rain/snow initially changing to snow for several hours before ending with some accumulation possible on elevated surfaces, and will also be most favored for IFR conditions -- with even a low chance of a brief period of LIFR at DBQ in heavier snow but too low confidence to include. Low clouds in the wrap-around will persist for much if not all of Saturday PM, with some clearing/ VFR developing late in the period at BRL and possibly CID/MLI. S/SE winds generally around 10 kts or less will turn N/NW and gusty at 10-20+ kts in the wake of the departing low. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...Winter Weather Advisory from 3 AM to 10 AM CDT Saturday for Benton-Buchanan-Delaware-Dubuque-Jackson-Jones-Linn. IL...Winter Weather Advisory from 3 AM to 10 AM CDT Saturday for Jo Daviess. MO...NONE. && $$ SYNOPSIS...Cousins SHORT TERM...Cousins LONG TERM...Gibbs AVIATION...McClure
Area Forecast Discussion
National Weather Service Grand Forks ND
1030 PM CDT Fri Apr 1 2022 .UPDATE... Issued at 941 PM CDT Fri Apr 1 2022 Showers are slowly making their way out of the area. FAR reported rain at the last observation, so some is hitting the ground. Temperatures are in the 30s and 40s currently across the area; look for lows in the upper 20s and low 30s tonight. UPDATE Issued at 633 PM CDT Fri Apr 1 2022 Showers are moving across the area this evening, no impacts are expected. Mainly producing virga, however, some spots have seen light rain. A clap or two of thunder cannot be ruled out, but no lightning has occurred in the CWA as of writing this. Tonight, winds should begin to shift to the west/northwest. Forecast is on track. && .SHORT TERM...(This evening through Saturday night) Issued at 301 PM CDT Fri Apr 1 2022 Precipitation chances and type tonight as well as temperatures tomorrow will be the main challenges for the period. Broad upper trough continues to rotate through the Plains States. One embedded vorticity max has been rotating through central SD and bringing some light precip to eastern portions of that state, although so far everything as been staying south of our border. Another, weaker vort max is entering western ND, and there has been a fair amount of cumulus development to our west with daytime heating. CAMs continue to show some showers pushing in across our southeastern ND counties this evening, and doesn`t seem out of the question with a few of the cu to our west starting to show some returns on radar. Will continue to keep some chances for precip mainly going south of the Hwy 2 corridor this evening. The NAM and HRRR have some MU CAPE values around 250 J/kg in a narrow band along the surface trough axis this evening as it enters southeastern ND. Given current MU CAPE analysis from SPC, there is already some weak instability out west and a clap or two of thunder is not out of the question. Put in an isolated thunder mention for a bit this evening, but should lose instability as we go into the night and dropping temps could even bring a bit of snow mixing in. Any amounts and impacts will be minimal. Tomorrow should be fairly quiet and a bit cooler with weak high pressure over the Plains and brief upper ridging between systems. Highs should be mostly in the 40s, with some low 50s possible in the west and upper 30s where there is snow cover in west central MN. The next shortwave trough begins to approach Saturday night, bringing increasing clouds and southeasterly winds. .LONG TERM...(Sunday through Friday) Issued at 301 PM CDT Fri Apr 1 2022 Main challenge for this forecast period is the potential for precipitation on Sunday and again for Tuesday. A vigorous upper level trof and attendant surface system will track across the northern Plains on Sunday. General consensus is the best chances for precipitation will be along the South Dakota border. By Monday, the trof departs and the upper ridge amplifies. Return surface flow and increased thicknesses will allow temperatures to climb, with low 50s expected for Monday. By Tuesday into Wednesday, the jet digs into the central Plains and another wave looks to cross the Dakotas. An inverted surface trof will cross the area and abundant moisture is available for measurable precipitation. Expect rain initially ahead of and along the trof, with cooler air and moisture wrapping behind the system where some measurable snow is possible as the low slows with a negative tilt trof aloft. By Friday, the low departs and temperatures rebound as more pleasant weather settles across the area. && .AVIATION...(For the 06Z TAFS through 06Z Saturday night) Issued at 1030 PM CDT Fri Apr 1 2022 Showers have cleared all the TAF sites, for the most part. Possibility for a sprinkle in Bemidji as we approach 06z. Clouds will yo-yo in height across the area tonight and Saturday, but should remain in VFR to MVFR levels. Clouds will mostly affect TAF sites in Minnesota, but could also seep into the Red River Valley. Winds will shift to northerly over the course of the day, then another wind shift to easterly will come in the evening on Saturday. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. $$ UPDATE...AK SHORT TERM...JR LONG TERM...Hopkins AVIATION...AK
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
919 PM CDT Fri Apr 1 2022 .UPDATE... Issued at 915 PM CDT Fri Apr 1 2022 No significant changes are needed to the forecast this evening. A surface low will develop east across northern Illinois through the day tomorrow, delivering a brief period of rain and some snow to the region. Large scale forcing is forecast to be quite impressive with this system, and mid-level lapse rates along its northern flanks will additionally steepen appreciably. The 00Z HRRR has shifted a bit farther north with the progged surface low track, and is now better-aligned with the multi-model consensus which shifts the low essentially right along or just south of I-80. Given the lack of a colder antecedent airmass, snow accumulations (on pavement) will likely be muted, even in the face of what could be brief heavier rates as intense DCVA pinwheels overhead through midday and early-afternoon. Any slushy snow accumulations will require these heavier/convective type rates, and with the northward shift in the HRRR, guidance is in pretty good agreement that this zone will exist mainly north and west of a roughly Amboy to St Charles to Waukegan line. In fact, the latest RAP-derived Bourgouin melting energies suggest that outside of a little mix as precipitation initially develops, locales farther south of I-88 will likely remain mainly rain. The going forecast handles the expected evolution of things well. Perfect-progging model output snow depth (likely a much better proxy for actual snow accumulations in this case) suggest up to 2 inches of snow back towards parts of Ogle, Winnebago, Boone, and northern DeKalb counties. Given expected window of higher rates, could see a little slush accumulate on secondary/elevated surfaces, but continue to suspect travel impacts will be limited (and more problematic may be the reduced visibilities in any heavier rates). Much of the snow that does manage to accumulate on grassy surfaces will probably be melted by late tomorrow evening. Carlaw && .SHORT TERM... Issued at 321 PM CDT Fri Apr 1 2022 Through Saturday night... The main forecast concern during the period continues to center around the threat for a period of wet snow across portions of far northern IL (primarily along and north of I-88 and west of the Fox Valley) on Saturday morning. While temperatures are expected to be hovering at or above freezing, some accumulations are possible with this activity (especially on grassy and elevated surfaces), due to the increased chances for heavier rates of snow in the morning. While this is the case, uncertainty continues to be higher than normal with overall snow accumulations and overall travel impacts beyond reduced visibilities. Our main weather marker for Saturday is an upper level short wave impulse currently noted in the water vapor imagery digging southeastward across eastern Montana. This impulse is forecast to dig southeastward and phase with a larger scale trough over Iowa and northern IL Sunday morning. The net result of this being the development of a compact surface low that will move eastward across the area during the day. The disturbance will undoubtedly produce precipitation across a vast majority of the area though most of the day. In most areas, the boundary layer will remain just warm enough for this precipitation to fall as a cold rain. However, there is concern that precipitation rates could become high enough to result in stronger column cooling and a shift over to a period of heavy wet snow Sunday morning, primarily over far northern IL. This concern for heavier precipitation rates revolves around the fact that forecast guidance is fairly consistent in developing a mesoscale band of 850-700 mb frontogenesis beneath the entrance region of an upper level jet streak right across far northern IL during the morning. The combined effects of this with the larger scale forcing for ascent would thus support a narrow band of enhanced forced mesoscale ascent, and hence an area of heavier precipitation rates potentially falling as heavy wet snow. Guidance continues to differ a bit on the favored location for this mesoscale area of frontogenesis, with some continuing to favor areas north of I-88 in and around the Rockford, IL region. However, other hi-res models suggest areas a hair farther south, closer to the I-80 and I-88 corridors. This adds uncertainty to exact placement of this possible area of snow, which may only be a county or so wide (~30 miles wide). Wherever this band of snow sets up the potential is there for a few inches (1 to 3 inches) of wet snow, but this may be mainly confined to grassy areas and elevated surfaces due to the most of the snow falling after daybreak. The early April sun angle will certainty make it difficult for much in the way of accumulation on paved surfaces, so actual travel impacts may only be limited to reduced visibilities, which could drop below a mile in the heavier snow. The potential for accumulating snow will generally begin to wane late in the morning and the afternoon as surface temperatures warm. Some rain will continue into the afternoon before it ends later in the afternoon following the eastward exit of the storm system. We have opted to hold off on issuing a winter weather advisory for the Rockford area given the possibility of limited travel impacts with this snow, but this will need to be monitored. KJB && .LONG TERM... Issued at 310 PM CDT Fri Apr 1 2022 Sunday through Friday... An active weather pattern will continue through next week, with high confidence in another round of precipitation (mainly or entirely rain) later Sunday into early Monday, and then additional chances in the mid to late week. Temperatures will average out near to a bit below normal through Wednesday, and then trend to solidly below normal to close out the work week. This will occur as a slow moving deep upper low meanders eastward, which may unfortunately bring the threat for the "S" word at times. Sunday will start out partly cloudy but trend to mostly cloudy in the afternoon upon the approach of our next system. High temps are forecast in the mid to upper 50s south of I-80 and lower to mid 50s north, except only 40s as is typical this time of year near the lake due to early lake breeze passage. A similar evolution to Saturday, but probably shifted farther north, is forecast Sunday night as a potent, compact short-wave and associated surface low track eastward. Some spotty light showers may break out near I-39 in the mid to late afternoon out ahead of the stratiform rain with some banded component Sunday evening night. Most of the guidance features a low track near or north of far northern Illinois, with exception of most recent Canadian global. Confidence is higher in rain as p-type, with moderate rates at times, though still can`t rule out farther south low pressure track and wet snow mixing in with northward extent. Could be some spotty showers lingering beyond sunrise Monday, but otherwise drying out. Monday`s forecast high temps are similar to Sunday, though warmer near the lake until mid-late afternoon lake cooling. Confidence is increasing in Tuesday being mostly dry, but we`re still holding onto some lower PoPs due to influence of recent GFS suites featuring a stronger and farther north southern stream wave. Suspect that the weaker and farther south scenario with dry easterly flow locally is more likely to win out, entailing 50s for most except 40s along and several miles inland of the Illinois lakeshore. A potent already closed off mid-level short-wave will eject from the Canadian Prairies to the northern Plains on Tuesday night. Meanwhile, a strong short-wave farther south (and strong upper jet) with associated surface low extending up to the mid MS Valley, will phase with the northern Plains short-wave into Wednesday. A band of rain showers will break out and rapidly shift eastward through Wednesday morning, with a brief warm sector bringing seasonable temps, followed by cold frontal passage. At this time, moisture return looks to be too little too late for noteworthy thunderstorm coverage and official mention in the grids, as steeper lapse rates look to arrive behind the cold front. Can`t rule out some isolated embedded thunderstorms in the warm advection regime Wednesday morning. Later Wednesday and onward, our weather will be influenced by the large upper low gyre that will form from phasing short-waves on Wednesday. While there is inherent uncertainty at this range, ensemble guidance remains in good agreement in crawling the upper low east-southeast through Thursday night and then east-northeastward Friday into next weekend (beyond current day 7). The pattern will be pseudo-blocky due to strong positive height anomalies surrounding the closed low and result in slow forward propagation of the upper low. The impressive cold pocket for April with 500 mb temps down to as cold as -30C or so will result in waves of showers associated with short-wave energy pivoting around the upper low gyre. These patterns with low tropopause heights and inherently steeper low and mid-level lapse rates can result in showers with graupel during diurnal instability maximum, which could be the case on Thursday. Northerly flow on the backside of the surface low reflection later Thursday night and Friday could allow wet snow to mix in if not a changeover, particularly Thursday night into early Friday. Highs will only be in the upper 40s to around 50 on Thursday and at best mid to upper 40s on Friday. Castro && .AVIATION... For the 00Z TAFs... Winds will settle SSE under 10 knots tonight amid VFR conditions. A compact low pressure will then move eastward across northern Illinois through the day Saturday. Precipitation type will depend heavily on the exact track of the low, with the expected track to be very close to or over Chicago. With this track, precip type in the Chicago metro will be primarily RA, with some SN mixing in for the first couple hours before low-level thermo profiles slowly warm. However, a farther south track by even less than 50 miles will significantly increase the chance of SN becoming the dominant precip type at ORD/MDW. In either case, the window of highest precip rates will be late morning into early afternoon, with periods of IFR visibility and a trend toward IFR ceilings expected. Wind direction will also depend on the exact track of the low, with confidence in direction low in the afternoon given the potential for the low to track over the Chicago terminals. The current forecast favors SE winds briefly becoming light NE or VRB before quickly backing NW around 10 knots by early evening. Kluber && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...None. && $$ Visit us at weather.gov/chicago Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/NWSChicago www.twitter.com/NWSChicago www.youtube.com/NWSChicago
Area Forecast Discussion
National Weather Service New York NY
1044 PM EDT Fri Apr 1 2022 .SYNOPSIS... Deepening low pressure continues to move northeast from the Canadian Maritimes overnight as high pressure builds to the west. The high then builds in for Saturday. An area of low pressure approaches from the west on Sunday and moves offshore Sunday night. Weak high pressure builds in on Monday and moves offshore by Monday evening. A complex frontal system will approach on Tuesday and bring unsettled weather to the area through the end of next week. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Another upper vort max was moving through the area as the associated upper trough moves offshore overnight. This was producing broken to near overcast conditions, with strato cu across much of the region. Updated temperatures and dew points for current conditions, and with the extensive cloud cover raised overnight lows, mainly inland, a couple of degrees. Gusty winds will continue through the overnight with the pressure gradient remaining fairly tight between the departing low and building high. Winds will begin to weaken toward morning. HRRR 10m gust potential depicts gusts starting to come down after 06Z. In addition, with the growing season starting today for NYC and immediate surrounding areas, some patchy frost may be possible by Saturday morning, with lows in the mid 30s. This is not expected to be widespread, but could be realized across parts of the area should winds subside earlier than currently forecast. Lows tonight generally in the mid to upper 30s across northeastern NJ, LI and NYC, and in the upper 20s to low 30s across CT and lower Hudson Valley. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/... Upper ridging builds in for Saturday and with subsidence aloft, a generally quiet sensible weather day is expected. With dry conditions and west/southwest flow, expect temperatures similar to Friday, a few degrees cooler given the lower starting point. Conditions remain dry Saturday night with increasing clouds as a low pressure system and attendant shortwave trough approach from the west. 12Z model guidance is showing a slightly stronger system than in previous cycles, with the upper trough slowing as it moves across the OH Valley into New England. Guidance is fairly consistent with the surface low tracking across PA and upstate NY Sunday morning and offshore by later Sunday afternoon. Have increased PoPs and QPF as a result, with total amounts around 0.15-0.20 inches during the day. Given the model thermal profiles early Sunday, there is a low potential for some snow to mix in at the onset of the precipitation across the far interior Hudson Valley, but this is not expected to be widespread or accumulating. Precipitation ends west to east by Sunday night. Highs on Sunday will be in the upper 40s across the interior, and low 50s elsewhere. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... Upper level trough axis shifts east Sunday night as low pressure moves offshore. Some rain showers could still be lingering over eastern portions of CT, but after midnight the area is expected to be dry. Skies clear from west to east, and depending on wind, some locations will be able to take advantage of radiational cooling and drop to their lowest temperatures of the long term period. Interior locations in CT and the Lower Hudson Valley will be the coldest, with lows in the lower 30s. Shortwave ridging approaches on Monday and flattens out as heights rise over the area. At the surface, weak high pressure briefly builds in, but the center passes to our south and west and slips offshore. Dry conditions with highs right around normal, low to mid 50s, can be expected. For the rest of the week, a broad upper level trough will be deepening over the central CONUS and slowly progressing eastward. This is well agreed upon by guidance, with -2 to -3 SD in 500mb heights from the Great Plains to the southeastern US in all Ensembles. Where guidance does disagree is how a piece of energy behaves in front of the aforementioned trough. The European and Canadian deterministic models pass this disturbance farther to our south along with surface low pressure. The GFS deterministic wants to bring this feature a bit farther north. Both situations will bring rain to our area. With moisture being brought northward from the Gulf of Mexico, the GFS is showing a PWAT value around 1.25 inches. This would allow for some moderate or even heavy rain showers. This value is above the 90th moving average for OKX based on SPC`s Sounding Climatology Page. As the aforementioned broad upper level trough continues to shift east, complex broad low pressure at the surface will result in unsettled weather through the end of the week. There will be a period on Thursday with a few hundred J/kg of MUCAPE across the eastern half of the area ahead of a cold front. With some elevated instability thunder can not be ruled out, but being this far out confidence in timing is low and have left out of the forecast for now. PWAT values look to be well above average on Thursday as well. Temperatures during the long term will be close to normal and have stuck closely to NBM. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... Deepening low pressure over the Canadian Maritimes will gradually pull away to the NE, while high pressure builds in from the west overnight into Saturday. The high moves offshore Saturday afternoon. VFR. A strato cu deck, 5K to 7K ft, has been moving into the area as the west to northwest flow continues behind departing low pressure, and will likely remain until toward morning. W/NW winds 15 to 25kt, gusting 25 to 30kt diminish overnight into Saturday morning with the gusts ending around midday. Winds veer to W then SW during Saturday afternoon, 10kt or less. Late day seabreezes develop. Timing of the diminishing winds and gusts may be off +/- an hour or two. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... West to northwest winds and gusts will be diminishing through the overnight into Saturday morning. Timing of the end of the gusts may be off +/- an hour or two. Sea breeze at KJFK may be earlier than 22Z. .OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY... .Saturday night...VFR. .Sunday...MVFR possible. Showers, possible brief mix with snow across parts of interior in the morning. Showers taper off in the evening. .Monday...VFR. .Tuesday...Chance of MVFR with any isolated showers early in the morning. .Tuesday Night-Wednesday...MVFR/IFR with showers likely. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... No changes to winds and seas at this time. Tight pressure gradient across the waters will continue to cause gusty northwest winds into early Saturday. SCA conditions continue for all waters with wind gusts 25-30 kt into this evening. Gale warnings remain in effect for the ocean tonight and through early morning Saturday as winds are expected to gust 35-40 kt ahead of a secondary cold front expected to move through tonight. Winds should diminish by daybreak Saturday morning but wave heights may remain elevated through midday to at least SCA thresholds on the ocean. Otherwise, sub-SCA conditions are expected on the non-ocean waters. As low pressure departs Sunday night, wind gusts on the ocean waters could briefly reach SCA criteria. Below SCA criteria then expected through Tuesday night. Winds become easterly ahead of a complex frontal system on Wednesday and seas begin to build. Seas likely remain above 5 ft through the end of the forecast period. During this same time, 25 kt gusts are possible on the ocean waters. && .HYDROLOGY... No hydrologic impacts are expected through the end of next week. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until 6 AM EDT Saturday for ANZ331-332- 335-338-340-345. Gale Warning until 4 AM EDT Saturday for ANZ350-353-355. && $$ SYNOPSIS...DBR/JT NEAR TERM...DBR/MET/JT SHORT TERM...DBR LONG TERM...JT AVIATION...MET MARINE...DBR/MET/JT HYDROLOGY...DBR/JT