Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/24/23


Area Forecast Discussion
National Weather Service Boston/Norton MA
1128 PM EDT Sun Apr 23 2023 .SYNOPSIS... Cloudy with areas of fog overnight. May see some clearing across CT/RI as a dry slot punches in, but uncertain given relatively light winds. The weather pattern remains unsettled through the upcoming week, with daily opportunities for isolated to scattered rain showers. Temperatures near to below normal. Periods of rain expected this week due to a mid-level feature stuck over New England. Though do not expect any heavy rain or washouts. Temperatures remain at or slightly below normal for the rest of the week into the upcoming weekend. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... 11 PM Update... Precipitation at this point has exited. Still a tricky forecast with regards to visibilities/cloud cover. Have a low over our area now with a dry slot punching into western areas. This is perhaps bringing enough of a pressure gradient that is allowing the fog to lift, but in most spots the low stratus is lingering. The only exception is across eastern areas, where the fog/stratus persists. Thinking that the pressure gradient slackens a bit late tonight, which will allow more widespread fog to develop. Some uncertainty here with the dry slot punching in, stratus overhead and weak NWly wind component. At this point have fog becoming more widespread once again late tonight into early Mon, but will need to closely monitor as guidance is a bit all over the place. Not out of the question fog could be dense in spots. Temps bottoming out in the 40s. 830 PM Update: The heaviest rain has moved out, remaining showers extend from Cape Ann to the south shore of Boston and to the outer Cape. The HRRR suggests that the rain should be long gone between 02z/04z. That said, CIGs are only a few hundred feet tonight east of the CT River, areas of mist/drizzle likely overnight. Wind does turn more out of the NW this evening and into the overnight, given the flow is weak, areas of fog are likely to develop and could become locally dense by tomorrow morning across eastern MA and into RI. Following shifts will need to monitor for any changes. Temperatures hold steady overnight only dropping a few degrees at most tonight. Coldest spots are found in the northwest corner of MA where lows dip in the upper-30s, while the rest are in the middle and upper 40s. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... The synoptic pattern will slowly evolve during this portion of the forecast. Will still be dealing with a deep mid level cutoff over the Great Lakes and portions of southern Canada. It will be some time before a weak surface low pressure and its frontal boundaries will move far enough offshore to no longer impact our weather. Currently thinking a low pressure reaches the coast this evening, but it will not be until Monday night before it will move from just off the east coast of MA into the Gulf of Maine. While this should mean plenty of lift nearby, not every aspect of the forecast will be as steady, namely the amount of moisture. Thinking the brunt of humidity will move north of southern New England for Monday into Monday night. Thus, once we get past the current steady rainfall, we would only be looking at the possibility of hit-and-miss showers from late tonight into Monday Night. Not a total washout by any means. No large swings in temperatures anticipated, with generally below normal high temperatures and above normal low temperatures. && .LONG TERM /TUESDAY THROUGH SUNDAY/... 330 PM UPDATE: Highlights... * Periods of showers expected this week due to a mid-level feature stuck over New England. Though do not expect any heavy rain or washouts. * Temperatures remain at or slightly below normal for the rest of the week into the upcoming weekend. Overview... STUCK. That is the word that comes to mind for this coming week with the mid-level low STUCK over the northeast due to a blocking feature down stream. As the week goes on shortwave energy pivots around the broad cyclonic flow, this continues rain chances well into the week ahead. Beyond the end of the week forecast confidence lowers because the continuity between model runs are not the best. For now, come Friday or Saturday the mid-level low seems to be absorbed into a cutoff low south of Greenland with mid-level ridge developing into next weekend. Precipitation... After a soggy weekend, the week ahead does not feature significant rain, more or less isolated to scattered rain. PWATs for much of the week range between 0.3 and 0.5 inch, which is slightly below normal for late April. As previously discussed the timing of said showers are difficult to nail down due to the positioning of the mid-level low and timing when individual shortwaves move across the CWA. Aloft temperatures are cold, around -25C to -30C. And that cold pool aloft does not exit the region until Friday night/Saturday. When you have such cold air aloft it does steepen lapse rates during the day when surface temperatures warm. Clouds and showers are likely to be driven by the diurnal heating and in conjunction with the passage of numerous shortwaves. A look at the multi-run trends for storm total precipitation, most the CWA receives a few hundredths of an inch of new precipitation through Friday/early Saturday. More or less nuisance showers are the theme of the week. Temperatures... Cooler period this week with temperatures at or slightly below normal for late April. 850mb temperatures are fairly consistent on either side of 0C. This results in daily highs in the upper-50s to low-60s. Tuesday night into Wednesday morning looks to be our coolest morning this week, with the northern hills of northern Massachusetts dipping into the low-30s. Which will need to monitor for frost given the frost/freeze program has started for our northern zones. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Tonight...Moderate confidence. Mainly IFR to LIFR overnight, with pockets of MVFR across the CT River Valley. Rain continues to slide NNE and exits the east coast of MA between 02z/03z. With low CIGs can not rule out mist or drizzle. Wind becomes NW/NNW. Monday...Moderate confidence. IFR-LIFR ceilings from ORH eastward, IFR-MVFR ceilings for BDL/BAF. BR/FG with periods of drizzle, though may see ISO/SCT SHRA during the mid-morning thru mid-aftn. NW winds 4-8 kt interior; light SE winds flip to SW around 4-8 kt for RI and Cape/Islands; eastern MA sees ESE/E winds become NE then NW with speeds mainly 5 kt or less. Monday Night...Moderate confidence. Mainly VFR, with local MVFR possible. Slight chance SHRA. KBOS Terminal...Moderate confidence in TAF. Low confidence in fog tonight. KBDL Terminal...Moderate confidence in TAF. Low confidence in fog tonight. Outlook /Tuesday through Friday/... Wednesday: VFR. Slight chance SHRA. Wednesday Night through Thursday: Mainly VFR, with local MVFR possible. Slight chance SHRA. Thursday Night: VFR. Friday: Mainly VFR, with local MVFR possible. Breezy. Slight chance SHRA. Friday Night: VFR. Breezy. Slight chance SHRA. Saturday: Breezy. Chance SHRA. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Little overall change with marine forecast. Small Craft Advisory conditions continue for some waters into Monday, and in the case of the outer coastal waters, into Monday night. Expecting poor visibility less than 1 NM at times. Gusty SE winds also develop overnight and continue into Sunday. A cold front should approach the eastern waters/cross the southern coastal waters late tonight. The timing of this front is not certain. but could take into Monday night before finally moving east of all the waters. Outlook /Tuesday through Friday/... Wednesday through Wednesday Night: Winds less than 25 kt. Thursday: Winds less than 25 kt. Slight chance of rain showers. Thursday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Friday: Winds less than 25 kt. Seas up to 5 ft. Slight chance of rain showers. Friday Night: Low risk for Small Craft Advisory winds with gusts up to 20 kt. Areas of rough seas. Slight chance of rain showers. Saturday: Winds less than 25 kt. Areas of rough seas. Chance of rain showers. && .HYDROLOGY... * Heaviest rains come to an end across eastern MA this evening ending the urban/poor drainage flood threat. Continue to monitor Farmington River in Simsbury tonight as levels continue to rise. Rain has ended for most, with the back end of the rain exiting eastern Massachusetts as of 00z. Anticipate it will take another hour or two for the back edge to clear Cape Ann and Cape Cod. As for the flood threat, smaller rivers and streams have crest and are receding. For the rest of the night we will continue to monitor the Farmington River in Simsbury as forecast show levels continuing to rise as the smaller tributaries empty into the Farmington. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 8 AM EDT Tuesday for ANZ250-254. Small Craft Advisory until 8 PM EDT Monday for ANZ255. Small Craft Advisory until 1 PM EDT Monday for ANZ256. && $$ SYNOPSIS...Belk/Gaucher/BL NEAR TERM...Belk/BL/Gaucher SHORT TERM...Belk LONG TERM...Gaucher AVIATION...Belk/Gaucher MARINE...Belk/Gaucher HYDROLOGY...
Area Forecast Discussion
National Weather Service Green Bay WI
1020 PM CDT Sun Apr 23 2023 Updated aviation portion for 06Z TAF issuance .SHORT TERM...Tonight and Monday Issued at 248 PM CDT Sun Apr 23 2023 Another cloudy and cool April afternoon with temperatures in the middle 30s to lower 40s. For the rest of the afternoon into this evening, a weak surface trough will sink southward across the area. Models are considerably drier compared to yesterday. The HRRR model is the most aggressive with scattered rain/snow showers developing across the area. Per coordination with surrounding offices, have lower the chances although some models would suggest the entire area would remain dry. Based on radar trends upstream, do think there will be isolated rain/snow showers around the area until mid evening. Sky cover later tonight will be problematic as bufkit soundings indicated cloud cover would linger through much of the night. The latest satellite trends would suggest skies should become partly cloudy. Previous forecast leaned that way and will continue those forecast sky trends. It will be very cold with lows in the upper teens and 20s. On Monday, a stronger upper level system will drop southeast into the area. This feature, combined with cold air aloft and areas of low level convergence will bring scattered rain/snow showers to the area from late morning into Monday evening. No real significant chances to precipitation chances on Monday compared to the previous forecast. Highs Monday will be in the 40s to around 50. .LONG TERM...Monday Night Through Sunday Issued at 248 PM CDT Sun Apr 23 2023 No significant changes to the extended portion of the forecast. A very messy and disjointed large-scale pattern with low predictability with a variety of mainly weak embedded disturbances in both the northern on southern streams. Overall, with limited available moisture and the western Great Lakes mostly dominated by northwesterly flow, precipitation amounts through much of the work week will be below normal. Monday Night and Tuesday: A couple weak impulses will be rotating around the southern periphery of elongated closed upper-level low pressure and will bring scattered mostly diurnal rain and snow showers. Early Monday evening, an associated weak surface trough will be dropping southward across the forecast area and although any remaining weak instability will be waning, consensus of the model guidance does hang onto some light rain and snow shower activity that will most likely impact areas along and north of Highway 29 through 06Z or so Tuesday. Only scattered amounts generally less than a tenth of an inch is expected with minimal impacts. Then during the day on Tuesday, a secondary weak shortwave impulse will drift across the forecast area above a post frontal cool boundary layer northerly flow. This will likely keep plenty of clouds across the forecast area and may also contribute to some very light and scattered diurnal rain and snow shower activity once again. On Tuesday night, weak high pressure will build quickly across the forecast area. However, boundary layer flow will remain out of the north so expect some lake-enhanced SC to persist especially north of Highway 29 with clouds becoming somewhat more scattered over southern areas. Overnight lows will be mostly in the 20s. Wednesday and Wednesday Night: Weak surface high pressure should remain in control with dry weather expected. Boundary layer winds will still be out of the north and northeast thus would expect some clouds around especially across the north. Highs on Wednesday will moderate somewhat with highs mostly in the 45 to 50 degree range and overnight lows in middle 20s north to lower 30s south, which is close to the blended guidance. Thursday and Thursday Night: After a quiet start with some early sun, a more potent shortwave will be approaching the upper Mississippi Valley region late Thursday and Thursday night. Although moisture looks to be limited with this system, mid-level PVA and associated low-level WAA should be fairly robust leading to an area of mainly light rain and rain shower activity that will skirt across the far north Thursday night. Overnight lows will continue to moderate within a modest southeasterly flow with lows in the 30s to around 40. Friday: Most long-term guidance suggests that heights will build substantially across western Canada on Friday which will allow for a deepening trough across the northern Plains by Friday afternoon. Associated surface low pressure will develop and deepen over the eastern Dakotas leading to a broader area of showers and isolated thunderstorms to develop late in the day. At this time, it is too early to determine how far east this activity will get but latest ensemble model guidance suggests that the activity should remain west of the forecast area through about 12Z Saturday. The forecast area will likely be embedded within a broad WAA regime, thus expect a fair amount of clouds on Friday which will likely hold temperatures in the 55 to 60 degree range which is closer to normal for late April. && .AVIATION...for 06Z TAF Issuance Issued at 1018 PM CDT Sun Apr 23 2023 Some decrease in clouds is expected overnight, but clouds will reform in the 14-15Z time frame tomorrow as the convective temperature is reached. Bases are expected to be high enough to result in primarily VFR conditions. An uptick in shower activity is expected tomorrow (compared to Sunday) as a vort digging southeast from Ontario causes the large scale trough to sharpen across the area. && .GRB WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM.....Eckberg LONG TERM......ESB AVIATION.......Skowronski
Area Forecast Discussion
National Weather Service Gray ME
1046 PM EDT Sun Apr 23 2023 .SYNOPSIS... A prolonged period of cool and unsettled weather will continue tonight and persist through early this week as a frontal boundary stalls over New England. This front will bring a widespread wetting rainfall to the area. Showery weather is then likely to persist through the middle of the week as an upper level low crosses over the region. Drier conditions and slightly warmer temperatures are then possible for the end of the week. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... 1045 PM Update...No significant changes at this time, just some minor adjustments to account for trends in observational data. 640 PM Update...Have updated the forecast for the balance of the evening hours, mainly to tighten up PoPs as there`s still a pretty tight gradient on the front of the rain shield. It will still take some midcoast and Central ME zones several hours to see measurable rain. Otherwise, adjusted temperatures down a bit where it is raining. Several NH rivers will see action stage tonight but no flooding is expected. Previously... Mesoscale models continue to pivot the rain shield to the east overnight with the latest HRRR and NamNest solutions suggesting the heavier and steadier precipitation will mostly be confined to Maine by the 00Z-02Z timeframe. This is where the best dynamics will be situated overnight with lighter precipitation over New Hampshire. A rumble of thunder remains possible through this evening as well. Ptype will be in the form of rain as suggested by atmospheric profiles. The exception will be the higher peaks of the northern mountains. The sleet and freezing rain as of 18Z will change to snow overnight as heights fall across the region. It will be chilly and raw with lows in the 30s to lower 40s except cooler in the mountains. With plenty of low level moisture in place, have added additional fog to the overnight forecast which is in agreement with the latest HREF solution. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... The steady precipitation diminishes on Monday, however Pops will still remain high across the region. Guidance has backed off on the heavier precipitation over the last few days and is currently more progressive with the deeper moisture shifting to the east on Monday. Nevertheless, plenty of upper level support will allow for periods of light rain and raw, chilly conditions for this time of the year. Afternoon highs will only be in the 40s in most areas with accumulating snow over the highest peaks. Not much change in conditions are expected Monday night with perhaps the best chance for any additional light precipitation shifting to central and northern areas. && .LONG TERM /TUESDAY THROUGH SUNDAY/... The extended period begins as moderate precipitation tapers off becoming more scattered and showery as a stalled frontal boundary remains draped across the area through the week. An upper level blocking high continues to remain centered over Newfoundland/Labrador, finally eroding at the end of the week. This leave a cluster of upper level shortwaves reaching from the Great Lakes to New England through Wednesday before brief ridging allows these shortwaves to disorganize Thursday and Friday. Ensemble guidance then shows a few more shortwaves working their way southeast from their current position over the Aleutians and Gulf of Alaska towards the midwest, eventually reforming a broad upper level low across the Great Lakes and New England late next weekend. After a lengthy frontal passage, rainfall becomes more scattered and showery on Tuesday as unsettled conditions linger bringing light precip through Thursday, becoming lighter with time. Clouds and onshore flow will keep temperatures down along the coast through the week. Towards the end of the week the shortwaves moving south from Alaska mentioned earlier begin developing a surface low over the central CONUS. The location, track, and strength of this potential low are still highly uncertain so I have just gone with a general chance PoP for late in the weekend when we could see potential impacts from this system. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... Short Term...IFR or lower conditions expected overnight in areas of rain and fog. Low ceilings to continue on Monday into Monday night. Long Term...Unsettled conditions linger through the first part of the long term as widespread showery precip brings reduced ceilings and visibilities. MVFR ceilings and -SHRA restrictions will likely remain scattered across the terminals through Wednesday before conditions begin improving Thursday and Friday. && .MARINE... Short Term...Have expanded SCAs to include the bays in this latest forecast package. Casco Bay will continue headlines through Monday with Penobscot Bay beginning SCAs during the day Monday. Long Term...Seas will be subsiding Tuesday morning from SCA thresholds with waves at 2-4ft by the evening. Some marine fog may be possible as moisture and showers linger over the waters with onshore flow during the days. Seas then begin building again at the start of the weekend with another potential low pressure system approaching. && .HYDROLOGY... A cold front will stall over the region tonight through Monday. This will result in a general 1-2 inches of rainfall in Maine. Elsewhere, between 0.50-1.00" can be expected. Showery weather then will continue through mid-week, although additional rainfall amounts will likely be low. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory until 6 PM EDT Tuesday for ANZ150-152-154. Small Craft Advisory until 6 PM EDT Monday for ANZ151. Small Craft Advisory until 6 PM EDT Monday for ANZ153. && $$ SYNOPSIS... NEAR TERM...Ekster SHORT TERM...Cannon LONG TERM...Thunberg AVIATION... MARINE... HYDROLOGY...
Area Forecast Discussion
National Weather Service Wilmington NC
1018 PM EDT Sun Apr 23 2023 .SYNOPSIS... Weak cold front will push across the area and just offshore late tonight or early Mon before stalling. High pressure will follow Mon and persist thru Tue. Low pressure systems will periodically affect the area Wed thru Fri with unsettled weather conditions at times. Their tracks will generally remain just south and east of the forecast area. && .UPDATE... Some tweaking applied to the sky coverage based on latest mid and upper level cloud movement via sat imagery. Applied a degree or 2 tweaks lower to the Min and hrly temps based on latest trends along with latest HRRR guidance. Just enough rad cooling may bring mins to 50 in the vicinity of the ILM/CHS CWA border. Winds will veer to the W-NW 5 mph or less prior to the cfp during the pre-dawn Mon nrs. After fropa, NNW- NNE 5 to 9 mph, may take until 1-2 hrs after sunrise Mon for the CFP to clear the coast. && .NEAR TERM /THROUGH MONDAY/... Another cold front will drop through the area overnight into Monday, bringing an increase in clouds overnight into Monday with cooler temperatures for Monday. Lows tonight will fall to the low to mid 50s with highs Monday near 70, give or take a degree or two. && .SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/... Clear and cool overnight allowing radiational cooling to bring temperatures into the mid and lower 40s by Tuesday morning. High pressure maintains quiet weather on Tuesday with the air mass moderating slightly with onshore flow. Slightly warmer with highs in the low to mid 70s. Mild overnight, dropping into the low to mid 50s. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... An extended period of unsettled weather develops on Wednesday with a stationary front to our south. Surface lift will provide light shower chances in response to a weak trough developing SW to NE from southern GA through eastern NC. With the trough and mid level shortwave moving offshore, a surface low will strengthen off of the NC coast, maintaining shower chances overnight. A larger shortwave will approach the area late Thursday as the stalled frontal boundary begins to surge northward from northern FL and southern GA. Showers remain possible during the day on Thursday, but is likely to the be the lull between two disturbances. Unsettled weather and showers increase Thursday evening into Friday with low pressure navigating around the shallow wedge of high pressure over the Carolinas. Models continue to illustrate important differences in deterministic and ensemble solutions. Uncertainty in exact impacts remains high, but unsettled weather through Friday appears likely regardless of the timing. Next weekend`s weather will depend on the preceding pattern, but a brief warm up may precede a strong cold front at some point during the weekend. && .AVIATION /02Z MONDAY THROUGH FRIDAY/... VFR conditions to dominate through the 24 hr valid taf issuance period. Mid and upper level clouds to eventually move overhead later tonight thru the Mon as a cold front drops across and eventually east of the area during Mon before stalling. No pcpn being fcst at this time. Timing of the CFP and the wind direction changes will be the problem childs. After FROPA, winds will generally become NNW-NNE around 10 kt thruout. Extended Outlook...VFR into Tue. Potential for flight restrictions increase Wed thru the end of the week due to a series of disturbances developing and moving along a stationary front south and east of Northeast SC and Southeast NC. && .MARINE... Through Monday... For tonight, expect SW winds of 5 to 10 KT to become W then N to NE around daybreak Monday. Speeds may increase to 10 to 15 KT at times Monday. Seas will generally run 2 to 3 FT through the period. Monday Night through Friday... High pressure builds into the area through early next week, maintaining quiet marine conditions on Monday and Tuesday. A weak disturbance will develop along the immediate coast late Tuesday into Wednesday, increasing winds and seas for a brief period. Unsettled weather continues late next week with elevated winds and seas. Confidence in the forecast beyond Wednesday evening is low. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ SYNOPSIS...DCH UPDATE...DCH NEAR TERM...31 SHORT TERM...21 LONG TERM...21 AVIATION...DCH MARINE...21/31
Area Forecast Discussion
National Weather Service Jacksonville FL
906 PM EDT Sun Apr 23 2023 ...New UPDATE... .UPDATE... Issued at 900 PM EDT Sun Apr 23 2023 This evening, weak sfc high pressure ridge is located near the GA coast as another cold front is moving into central GA and parts of the Carolinas. The front will continue pushing southward tonight and Monday morning, while shortwaves move into the area from the west. These will be accompanied by increasing cloudiness through the night. No rain chances are indicated for the area tonight given the very dry airmass to start off tonight. Enhanced forcing aloft and much more moisture for Monday will bring a chance of showers and possibly a thunderstorm for the southern zones. For the update, some adjustment made to lower temps slightly tonight, and then for Monday we upped the rain chances a bit for the southern most zones, but tapered back the t-storm chances a bit given the very weak instability. Little change in the CWF update with just minor changes for winds and seas for rest of tonight. && .NEAR TERM... (Through Tonight) Issued at 248 PM EDT Sun Apr 23 2023 Beautiful weather is expected to continue this evening, with dry air present ahead of a wet week. Low temperatures will be in the upper 50s to mid 60s, with calm winds and sky cover gradually increasing towards sunrise. && .SHORT TERM... (Monday through Tuesday night) Issued at 248 PM EDT Sun Apr 23 2023 Mostly cloudy skies as moisture returns on Monday will keep high temperatures in the mid to upper 70s for most of southeast Georgia and northeast Florida, with areas south of Gainesville and west of I-95 possibly hitting the lower 80s. In the late morning / early afternoon some scattered showers will begin to fill in from the southwest, with the highest chances for isolated thunderstorms being in northeast Florida east of I-75. Tuesday will be a few degrees warmer than Monday, with more widespread scattered showers and thunderstorms expected due to sea breeze convergence paired with moisture ahead of a frontal system. && .LONG TERM... (Wednesday through next Sunday) Issued at 248 PM EDT Sun Apr 23 2023 Wednesday is looking like the most active day, with widespread thunderstorms and heavy rainfall likely as a warm front moves over our area. The best chances for strong to severe storms along with heavy rainfall will be Wednesday, but with more precipitation forecasted for Thursday, rainfall flooding may linger through Thursday night. As of now, Saturday is looking like the only dry day during this period, another cold front approach from the northwest Saturday night into Sunday. Friday and Saturday will be warmer than normal, with Wednesday, Thursday, and Sunday seeing temperatures near climatology. && .AVIATION... (00Z TAFS) Issued at 750 PM EDT Sun Apr 23 2023 VFR expected through much of this period. However, expect to see increasing multilayered clouds by Monday morning as a weak low pressure system approaches from the west and an upper level disturbances passes over the region. Sky cover expected to turn broken to overcast. Some shower activity is expected to push into parts of northeast and north central FL by mid to late day Monday. For now, have VCSH for GNV and SGJ and a PROB30 group for showers. Left showers out of JAX metro northward as the HRRR model guidance focused convection south parts. MVFR cig or vsby chances with showers in the aftn are low. The t-storm probabilities look pretty low so not included at this time. Tonight, sfc winds will become light and variable or light from the northeast or east. Breezy northeast flow expected for SGJ, SSI, and CRG after about 14z Monday. && .MARINE... Issued at 248 PM EDT Sun Apr 23 2023 High pressure will settle north of the waters tonight and Monday. A warm frontal boundary will lift northward into the waters on Tuesday with a low pressure system tracking along this boundary on Wednesday and Thursday, which will bring abundant showers and thunderstorms over the local waters through the end of the week. Rip Currents: Moderate rip current risk expected Monday and Tuesday for NE FL and SE GA beaches. && .PRELIMINARY POINT TEMPS/POPS... AMG 54 76 55 79 / 0 10 10 20 SSI 61 75 63 74 / 0 20 20 30 JAX 56 78 60 78 / 0 30 20 40 SGJ 63 76 63 76 / 0 30 30 40 GNV 57 80 60 79 / 0 40 20 40 OCF 59 81 61 82 / 0 50 20 50 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$
Area Forecast Discussion...UPDATED
National Weather Service New Orleans LA
932 PM CDT Sun Apr 23 2023 ...NEW UPDATE... .UPDATE... Issued at 926 PM CDT Sun Apr 23 2023 The region resides under the northern cirrus shield from the MCS over the western Gulf of Mexico this evening. This blanket of clouds will help insulate and limit radiational cooling...along with the gradual increase in northeasterly winds behind a cold front moving southward through our region. Inherited sprinkles for this evening, but took those out after looking at the 00z LIX RAOB with extremely dry low levels. Kept silent POPs respectively, but most of us should only see mostly cloudy skies overnight. Otherwise, no changes to the overnight forecast with winds picking up over the marine zones and Monday looking very mild...but breezy with overall decreasing clouds expected as drier air tries to work into the mid and upper levels, especially later in the day. (Frye) && .SHORT TERM... (This evening through Monday night) Issued at 133 PM CDT Sun Apr 23 2023 Starting things out with this afternoon, mid/upper-level clouds continue to build in from the west per recent GOES-16 Ch2 VIS imagery and obs. This is largely what was left of some stratiform rain left over from convection over central Texas last night that continues to spread east along quasi-zonal westerly flow aloft. However, within this flow there is a very subtle reflection of a shortwave impulse/PVA riding east with some weak returns being picked up long range from KLIX entering our western CWA as of early afternoon. While dynamic lift is subtle, its enough to get virga going in this region up above a dry surface to H7 layer situated in place. As discussed in the forecast update this morning, this layer across western areas has moistened up some reaching around 40-45% RH layer average in the surface to low/mid- level layer, meaning some of these returns might not have much trouble reaching the surface, especially brighter returns at times. Went ahead and bumped up PoPs to follow this impulse east this afternoon/evening to 10-15%, with drizzle mentioned from 10-14%. Hardly, if any measurable QPF can be expected but perhaps can`t rule out 0.01-0.05" if this stuff starts to look more impressive versus now. But, this impulse is going to be bumping up against even drier low-level air as it tracks east. Much drier air resides in this same layer over coastal MS following afternoon mixing, but will respond slowly by wet bulbing with time moistening from the top down. Just not overly confident mentioning rain chances east of I-59, but can`t fully rule it out. Meanwhile, a pretty impressive MCS has taken shape across far southern Texas, which HRRR runs initializes well by continuing this complex ESE to eventually SE into the western Gulf. This will add to the increase in clouds as the anvil canopy spreads NE into our vicinity. Next question will be now far north can the stratiform precip shield make it overnight for our area. Once again, not confident for areas north of I-10/12 but did go ahead with 15% mention for coastal SE LA as this shield grazes us over marine areas. Probably a bit more QPF potential for marine zones but should refrain from being a significant issue. At the same time, a weak frontal boundary just to our north will continue to slide south as identified by a noticeable thermal gradient and reinforcing NE wind shift over central/southern MS. This will continue to push south overnight tonight with a slight uptick in surface winds. May become rather gusty at times across north- facing shorelines like across the immediate Southshore, but mainly will act as a reinforcement for CAA keeping temperatures chilly again around daybreak. Going into Monday, things look quiet as very weak/broad mid-level ridging builds in from the west and clouds try to depart slowly but surely. High pressure takes a bit more control over the area owing to a rather nice day with warm afternoon temperatures. Next focus will be with a developing system over the central/southern Plains downstream of the next pacNW shortwave trough diving ESE into the central Rockies. This in turn aids in downstream divergent flow supporting broad, large scale lift and eventual low-genesis along the leeside of the Rockies. Showers/storms get going over the southern plains/ArkLaTex region late Monday night, but even beyond the short-range, greatest lift remains well to our north away from our area leading to a likely dry forecast going into the day on Tuesday. KLG && .LONG TERM... (Tuesday through Saturday night) Issued at 133 PM CDT Sun Apr 23 2023 Tuesday through Thursday, a shortwave trough is expected to move through the area, enhancing the chances for rain mid-week. Easterly to southerly surface winds will help to advect some warm air and moisture into the area. Scattered to numerous showers and storms will be likely Tuesday into Wednesday, but model consensus continue to be unclear regarding the timing and amount of rainfall. Shear at the moment will be generally low. So, there could be a strong to severe storm, but looking at the models, widespread severe weather potential is not expected for now. But, there will be the potential for localized flash flooding with these storms, especially if they set up along a lingering boundary. It is still too early to tell the strength of the system and specific timing, due to a decent lack of model consensus especially regarding some of the timing. We will keep monitoring this system as it develops. MSW && .AVIATION... (00Z TAFS) Issued at 601 PM CDT Sun Apr 23 2023 VFR conditions expected through the cycle. Mid and upper cloudiness will continue to stream north and east. A surface cold front will continue to gradually shift southward through the area this evening shifting winds to a more northeast direction. Winds could gust up to 20-25kt for MSY and NEW with the flow off the lake later tonight and early Monday. (Frye) && .MARINE... Issued at 133 PM CDT Sun Apr 23 2023 Persistent early flow will continue this evening into tonight as clouds increase with light showers building in from the west. A weak frontal boundary will sag south into marine zones later tonight, owing to a steady increase in winds to small craft advisory criteria due to gusty offshore flow. Winds will taper going into the afternoon hours Monday as high pressure settles into the region. The next frontal boundary and associated showers/storms arrives on Thursday, with the next system possible this upcoming weekend on Saturday. && .PRELIMINARY POINT TEMPS/POPS... MCB 49 69 49 72 / 10 10 0 20 BTR 56 73 54 78 / 10 10 10 30 ASD 53 76 53 80 / 10 10 10 20 MSY 60 74 61 78 / 10 10 10 20 GPT 55 74 54 76 / 10 10 0 20 PQL 53 76 52 79 / 10 10 0 10 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...Small Craft Advisory from 1 AM to 1 PM CDT Monday for GMZ530-532- 534-536-538-550-552-555-557-570-572-575-577. MS...None. GM...Small Craft Advisory from 1 AM to 1 PM CDT Monday for GMZ532-534- 536-538-550-552-555-557-570-572-575-577. && $$ UPDATE...RDF SHORT TERM...KLG LONG TERM....MSW AVIATION...RDF MARINE...KLG
Area Forecast Discussion
National Weather Service Marquette MI
759 PM EDT Sun Apr 23 2023 .SHORT TERM...(Through this evening) Issued at 319 PM EDT SUN APR 23 2023 Water vapor imagery and RAP analysis show a broad mid-level low centered just north of International Falls. A number of shortwaves are wrapped in its expansive circulation, but none are affecting the weather over the fcst area this aftn. Springtime stabilizing influence of Lake Superior is evident over the western part of the lake where skies are sunny. This stabilizing influence is spreading inland across Gogebic/Ontonagon counties. Otherwise, clouds dominate this aftn, and so far, no diurnally generated showers have developed. The sct -shsn that were streaming into the eastern fcst area earlier today have dissipated or weakened to a few flurries/sprinkles. Temps are in the 30s F across the board. As weak daytime heating thru clouds continues, there may yet be some -shsnra or sprinkles/flurries that develop across portions of central Upper MI. If any pcpn develops, it will dissipate around sunset. Otherwise, clearing spreading into western Upper MI will continue to progress eastward into central Upper MI thru the evening. Over the eastern fcst area, nw flow with more extensive cloud cover upstream suggests clearing will not extend into that area tonight. Sharper low-level troffing will drop s across eastern Lake Superior overnight, and this may aid the development of a few -shsn late tonight to the e of Munising. With the clearing skies and winds falling off to light/calm, favored the lwr side of guidance (mid teens F) for min temps in the interior. Temps will range up thru the 20s elsewhere, warmest east along Lake Superior. .LONG TERM...(Monday through Sunday) Issued at 239 PM EDT SUN APR 23 2023 Upper air pattern consists of a 500 mb closed low over western Ontario which will slowly meander around and then finally end up over the lower Great Lakes by 00z Thu. Diurnal nature to showers will continue into Mon night and then it finally dries out as the upper low moves to the east. In the extended, the GFS and ECMWF show a 500 mb shortwave in the northern plains 12z Thu which digs into the upper Great Lakes 12z Fri. This shortwave remains over the area through Sun. Temperatures look to stay near normal for this forecast period. It also looks wet with a slow storm system remaining over the area Thu into the weekend. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 729 PM EDT SUN APR 23 2023 Some drying in the low levels under weak high pressure should result in VFR conditions at all terminals. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 239 PM EDT SUN APR 23 2023 As high pressure begins to build over Lake Superior this week, the wind will stay below 20 knots through Fri. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...Rolfson LONG TERM...07 AVIATION...Voss MARINE...07
Area Forecast Discussion
National Weather Service Spokane WA
413 PM PDT Sun Apr 23 2023 .SYNOPSIS... Tonight into Monday will feature periods of rain and mountain snow as a pair of systems move through the Inland Northwest. High pressure will build over the Western U.S. on Tuesday and will likely remain in place through the end of the week. Eastern Washington and north Idaho can expect several days of dry weather and above average temperatures during this time frame. && .DISCUSSION... Remainder of the afternoon into the evening: Bands of light rain have expanded across north Idaho and eastern Washington this afternoon. As of 2 PM, thinning of the cloud deck in north central Oregon up to Tri Cities and Moses Lake was aiding in the process of afternoon destabilization. With temperatures in south central Washington in the mid to upper 60s, the RAP analysis yielded 100-250 J/Kg of surface based CAPE. With a couple more hours of warming, look for scattered showers and thunderstorms to develop in the vicinity of a surface low emerging east of the Cascades around Yakima. As this low tracks northeast toward Moses Lake and Colville this evening, look for clusters of showers to track to the northeast. A few cells will be capable of brief heavy rain, pea hail, and lightning into the early evening. Overnight and Monday: A compact and quick moving 500mb low will move into northwest Washington late this evening and track to the southeast overnight reaching northeast Oregon by Monday afternoon. The track of this low will largely shadow the valleys of the East Slopes of the Cascades. The models continue to develop wrap around precipitation in the form of a transient deformation band across the Idaho Panhandle and far northeast Washington. A few spots in far north of the metro near Colville, Metaline, Priest Lake and Sandpoint could get upwards of a half inch of precipitation tonight with the combination of evening showers followed by wrap around rain on Monday. With snow levels above 4500 feet in the Panhandle and northeast Washington, snow accumulations will be well above where most people live. Other spots that will be favored for significant amounts of rain and/or snow overnight into Monday will be the Cascade Crest and the southern Idaho Panhandle. Stevens Pass has a 40 percent chance of 2 inches of slushy accumulation by mid Monday morning. The models also develop bands of moderate precipitation across the Camas Prairie toward Lolo Pass from early Monday morning into the mid afternoon. Localized amounts of a tenth to a third of an inch are being generated by the NAM, GFS, and ECMWF. With snow levels as low as 4000 feet in the morning, grassy accumulations aren`t out of the question around Winchester and Nezperce before temperatures climb into the low to mid 40s in the afternoon. Further west, clearing in the lee of the Cascades will help push high temperatures into the low to mid 60s in Wenatchee, Omak, and Moses Lake. Tuesday and Wednesday: Believe it or not, we are done talking about precipitation and below average temperatures. There is excellent model ensemble agreement that mild high pressure will begin to build over the Pacific Northwest Tuesday. It will be a flat ridge initially Tuesday and Wednesday allowing bands of mid and high clouds to move across the Inland Northwest. High temperatures on Tuesday will range from the upper 50s in valleys of north Idaho to the mid 60s in central Washington and the L-C Valley. Look for widespread 60s and a handful of low 70s Wednesday. /GKoch Thursday through Sunday: Ensembles show greater confidence in the amplifying narrow upper level ridge solution which allows for a continued dry and warming forecast peaking on Saturday. NBM suggests probability of equal or exceeding 70 degrees for Spokane International Airport at 50 percent on Thursday, 70 percent Friday, and 75 percent Saturday. Same ensembles shows some deamplification of the ridge Sunday suggesting a slight interruption of the warming trend and the introduction of a bit more clouds and perhaps spotty light shower activity near the Cascade Crest and Blue Mountains but confidence is not high at this point. Weak disturbances overtopping and/or dropping down the eastern edge of this ridge will bring wind shifts from the Northwest on Thursday and the Northeast on Friday as well as a slight increase in cloud cover. Thermal ridge at 850mb positioned over the Washington Coast Saturday allows for surface winds to blow more from the east Saturday. Increased uncertainty Sunday and beyond in association with the deamplification and/or displacement of the upper level ridge as the earlier referred to thermal ridge at 850mb looks to jump eastward and over the Cascades and North Idaho Sunday which may allow for a bit more cloud cover to stream overhead and the inclusion of very low pops and QPF over mountain locations late Sunday with low confidence in the solution. /Pelatti && .AVIATION... 00z TAFs: Clusters of showers and isolated thunderstorms should evolve from the cumulus building between Tri Cities and Moses Lake. They will track to the northeast with the 700-500mb flow about 25 to 30kts. Thunderstorms will be handled through TAF amendments. Another band of light rain is expected to develop across the eastern third of Washington around 10z and spread into north Idaho around sunrise. Ceilings of 1500-2500ft are advertised by GFS MOS as well as HREF guidance from roughly 12z to 20z for Spokane, Coeur d`Alene, Pullman, Lewiston, Sandpoint, Colville, and Kellogg. /GKoch && .PRELIMINARY POINT TEMPS/POPS... Spokane 41 56 36 60 37 67 / 80 50 10 0 0 0 Coeur d`Alene 41 53 37 57 37 65 / 90 60 10 0 0 0 Pullman 39 51 36 57 37 64 / 70 70 10 0 0 0 Lewiston 46 59 41 65 42 72 / 60 60 10 0 0 0 Colville 41 58 35 62 36 69 / 90 60 10 0 0 0 Sandpoint 41 51 38 55 38 63 / 90 70 10 0 0 0 Kellogg 40 48 39 54 37 63 / 90 80 20 0 0 0 Moses Lake 44 64 36 66 39 72 / 40 10 0 0 0 0 Wenatchee 42 60 39 66 41 72 / 10 0 0 0 0 0 Omak 43 63 37 66 39 70 / 40 20 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
704 PM EDT Sun Apr 23 2023 ...New UPDATE, AVIATION, MARINE... .UPDATE... Issued at 704 PM EDT Sun Apr 23 2023 GOES-16 visible imagery along with TBW 88D data show sea breeze induced cumulus field beginning to extend vertically into the atmosphere with a few showers showing up in Sarasota and Charlotte counties. The HRRR has shown this scenario since yesterday with potentially heavy showers and storms developing in Charlotte and Lee counties soon. For the evening update, have extended rain chances northward into Manatee county and increased chances a bit for Charlotte and Lee. If the HRRR verifies, will need to increase pops even more before the evening is done. Otherwise - the current forecast is on track with just some slight tweaks to winds near the coast. && .AVIATION... (00Z TAFS) Issued at 704 PM EDT Sun Apr 23 2023 Expecting primarily VFR conditions next 24 hours. For this evening, would not be surprised to see showers and storms develop near PGD, FMY, and RSW and may need to add VCTS there in later amendments. For Monday, lowering clouds with rain moving in from the Gulf during the day. Could see some MVFR conditions after 18Z but will keep out of TAFs for this cycle as confidence in location and timing is low. && .MARINE... Issued at 704 PM EDT Sun Apr 23 2023 Weak high pressure will result in mainly light east to southeast winds over the waters through Wednesday with afternoon onshore sea breezes near the coast. Winds will turn south and southwest ahead of a frontal boundary for the second half of the week. Several upper-level disturbances will bring chances for showers and storms through most of the forecast period starting Monday. && .PRELIMINARY POINT TEMPS/POPS... TPA 69 84 68 84 / 0 50 30 40 FMY 69 85 66 87 / 10 70 40 50 GIF 65 85 65 85 / 10 70 30 60 SRQ 67 85 66 85 / 10 50 30 40 BKV 61 85 62 86 / 10 50 20 40 SPG 71 84 70 84 / 0 50 30 40 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...None. Gulf waters...None. && $$ UPDATE/AVIATION/MARINE...Jillson DECISION SUPPORT/UPPER AIR...Giarratana