####018008441#### FXUS66 KPQR 040501 AFDPQR Area Forecast Discussion National Weather Service Portland OR 1001 PM PDT Fri May 3 2024 && .SYNOPSIS... Cool and wet this weekend as an upper low moves into western OR and northern CA, bringing a prolonged period of light to occasionally moderate stratiform rain late Friday through Saturday. Remaining cool Sunday through Tuesday with showers at times. Upper level ridging will then bring a quick warmup mid to late week, with high temperatures likely rising above 80 degrees across the interior lowlands by Friday. && .SHORT TERM...Friday through Sunday night...Surface weather analysis from 1pm Friday revealed a warm front/cold front pair over the coastal waters moving east towards the coast. This frontal system was associated with a broad area of low pressure centered around 400-500 miles west of Vancouver Island. A wave of moisture ahead of the aforementioned warm front has already resulted in light rain at the coast. This moisture will continue spreading inland Friday afternoon as the system's warm front lifts over the area. Once rain begins, expect a prolonged period of light to occasionally moderate stratiform rain across all of northwest OR and southwest WA through the day on Saturday as the trailing cold front pushes through. Precip will transition to showers on Sunday within the post-frontal environment. This system will have an abundant amount of moisture as IVT values max out around 300-400 kg/ms this evening. Models still show precipitable water values around 1 inch, which is about two standard deviations above normal for this time of year. There have been minimal changes the total QPF forecast with this system. Still expect around 1-1.5 inches for the interior lowlands, and 1.5-2 inches for the coast and mountains from late morning today to tomorrow (Saturday) afternoon. No impactful winter weather is expected for the Cascade passes today as snow levels will rise above 6500 to 7000 feet. Despite the impressive rain amounts for early May, no flooding concerns are expected as hourly rain rates look to generally be under 0.2 inches/hr, except under heavier showers on Sunday. HEFS probabilistic guidance continues to show a less than 5% chance of reaching action stage for the majority of rivers. Two rivers with the highest chances of reaching action stage are Marys River at Philomath (5-10% chance) and Tualatin River near Dilley (15% chance). As the low pressure system progresses southward toward California Saturday, cold air aloft will return and snow levels will fall back down to around 3500 to 4000 feet. Given the precip expected this weekend, another round of winter weather will impact the Cascades. A Winter Weather Advisory has been issued above 3500 feet for the North Oregon Cascades to the Lane County Cascades from 5 AM Saturday to 11 AM Sunday morning. These locations are forecast to receive around 4 to 10 inches of snow, except up to 16 inches for the highest peaks above 5000 feet. Those traveling through the passes this weekend should prepare for winter weather conditions. Meanwhile, the lowlands will continue to see rain showers through the weekend. -TK/Alviz .LONG TERM...Monday through Friday...The long term forecast is highlighted by a rapid change in the weather pattern from cool and showery conditions Monday through Tuesday to much warmer and drier conditions late in the week. Models and their ensembles continue to show a shortwave trough moving across Washington and Oregon Monday into Tuesday, bringing a shift from westerly flow aloft to northwesterly behind the trough axis. This trough will bring the continuation of cool and showery weather with high temps mainly in the 50s and snow levels around 4000 ft on Monday falling to 3000 ft on Tuesday. Beyond Tuesday, confidence is high for a rapid shift in the weather pattern from cool and wet to warm and dry. This abrupt shift is the result of an upper level ridge that is set to build over the region, and all four clusters shown in WPC's cluster analysis depict this ridge with varying amplitudes. The deterministic NBM currently suggests highs in the 60s Wednesday, 70s Thursday (except 60s at the coast), and 80s Friday (except low 70s at the coast). The coolest model solutions are similar to the NBM 10th percentile, showing inland high temps only peaking in the mid 70s on Friday. Meanwhile, the warmest model solutions show highs near 90 degrees from Portland to Eugene. Either way, temps will be running above normal for this time of year. The probability for high temps at or above 80 degrees on Friday is already at 70-80% across the interior lowlands, which is quite high for a forecast that is seven days out. Overall, the warmest temps of the year so far are likely to occur next weekend. This may draw some people to area rivers and/or lakes, but keep in mind water temps are still very cold and river currents will be swift with mountain snowmelt. We plan on actively messaging cold water safety tips late next week in preparation for the warm weather ahead, as cold water shock and hypothermia will be a very real risk for anyone who decides to take a swim. -TK && .AVIATION...Rain has spread across the entire CWA as a surface low approaches the coast and sends a cold front through the area. A deep upper level trough off the PNW coast will continue to drop southeast through Saturday. Conditions are mainly MVFR across the area with IFR conditions at KNOP due to low CIGs and some VIS restrictions from light to moderate rain. Guidance suggests a low to moderate (20-50%) chance of IFR CIGs developing across the interior valley periodically through 15Z. Confidence in IFR CIGs developing at any location during this time period is uncertain and sporadic so will keep mainly MVFR conditions in the forecast. Rainy cloudy conditions will continue through all of Saturday as the upper level trough dips toward southern Oregon and northern California through the day. Winds are currently our of the southeast around 5-10 knots but will gradually veer to the southwest through the night. Winds will turn more westerly Saturday afternoon around 10 knots. PDX AND APPROACHES...Mainly MVFR conditions will prevail through the TAF period as a potent system impacts the area. Light to moderate rain has overspread the entire metro and will persist through Saturday. MVFR CIGs will be maintained through the day with a low/moderate chance for IFR CIGs through 15Z but confidence is not high at any given location. It is more likely that CIGs will bounce back and forth between MVFR and IFR at times. Light southeast winds around 5 knots will turn more west/southwesterly through the night. Winds will turn westerly Saturday afternoon around 10 knots. -Batz && .MARINE... A cold front associated with a low dropping out of the Gulf of Alaska continues to spread rainfall across the region this afternoon. Winds associated with this feature have been gusting around 20-35 knots based on the very limited bouy observations available but at least this lines up well with the latest high- resolution guidance. The current Small Craft Advisory was expanded to include the inner waters south of Cape Falcon where gusts up to 25 knots are expected to occur with more regularity into the evening - although that's not to say isolated gusts of this magnitude won't be found further north. Winds ease this evening into Saturday morning, but expect to see a period of marginally steep seas (6 to 8 ft at 8 to 9 seconds) Saturday afternoon and evening over both the inner and outer waters. Otherwise, anticipate another burst of SW wind gusts near 20-30 knots Sunday into Monday morning before we begin a transition to a calmer weather pattern and eventual shift to N-NW winds Tuesday and Wednesday. -Schuldt && .PQR WATCHES/WARNINGS/ADVISORIES... OR...Winter Weather Advisory from 5 AM Saturday to 11 AM PDT Sunday for ORZ126>128. WA...None. PZ...None. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland www.twitter.com/NWSPortland ####018008338#### FXUS64 KHGX 040502 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 1202 AM CDT Sat May 4 2024 ...New AVIATION... .SHORT TERM... (This evening through Saturday Night) Issued at 407 PM CDT Fri May 3 2024 Showers and thunderstorms are continuing to work their way through the northern half of SE Texas this afternoon. Some of these have produced heavier downpours as they have trained across already saturated areas, which of course exacerbates the ongoing flooding in locations that have previously received excessive rainfall. Current SPC mesoanalysis shows an area of deep moisture convergence north of I-10 along with a pocket of 1000-2000 J/kg elevated CAPE. Both deep moisture convergence and CAPE appear to trend downward over the next few hours, which should consequently lead to a downward trend in showers and thunderstorms. A lull in activity is expected overnight into Saturday with isolated showers/storms possible. At this point, any additional rainfall will only delay improvement in the current conditions. That being said, the decision has been made to maintain the current Flood Watch through Sunday. Going a little deeper into the overnight hours through Saturday morning...Hi-res guidance has been pretty spread out run-to-run as far as what development occurs during the overnight hours. Current thoughts are that PWAT values remain in the 1.5-1.7" range south of I-10 and 1.3-1.5" north of I-10. 500mb analysis shows another potential shortwave moving across SE Texas during the overnight hours with pockets of PVA. I don't want to lean into the 18Z HRRR suggesting that the area will remain rain-free overnight while the 12Z HRRR brings a few showers/storms through the area...so have compromised by keeping PoPs on the lower end, and bearing in mind the current setup with deep moisture and repeated shortwaves. Saturday during the day appears to be fairly inactive as most of the activity will fire off well west of our CWA. Saturday night into Sunday will be the primary concern for the short- term (beginning of long-term). Another shortwave and pockets of PVA will track east across the area late Saturday night triggering an MCS structure. The MCS is projected to arrive along the western/northwestern CWA as early as Sunday morning (exact timing of arrival is more uncertain at the moment) and will move across SE Texas during the day Sunday. At the current moment the Flood Watch goes through 1 PM Sunday; however, this may need to be reassessed as this next system evolves. At this time additional rainfall totals of 1 to 3 inches and isolated higher amounts will be possible late Saturday night into Sunday. WPC keeps much of the area (with the exception of the immediate coast) in a Marginal Risk for Excessive Rainfall Saturday. Portions of the Brazos Valley and Piney Woods will be in a Slight Risk for Excessive Rainfall. For Sunday, WPC places the majority of the area north of I-10 in a Slight Risk for Excessive Rainfall with the rest of the area in a Marginal Risk. Impacts from excessive rainfall over the last few days are ongoing and any additional rainfall will exacerbate these impacts. Please continue to monitor the forecasts, follow instructions from local officials, and have multiple ways to receive warnings. Adams && .LONG TERM... (Sunday through next Thursday) Issued at 407 PM CDT Fri May 3 2024 As mentioned in the short-term, the beginning of the long-term period will feature a strong shortwave with an MCS that will impact SE Texas during the day Sunday. At the surface, a weak warm front will lift northward into SE Texas which will reinforce the warm and moist environment. At this time, projected additional rainfall amounts are in the 1-3" range with isolated higher amounts possible. Once the MCS exits the region, relatively dry weather is expected through much of the week. The forecast hazards shift from flooding to heat. Ground moisture is expected to stick around for awhile, and with 850mb temperatures reaching the 99th percentile Wednesday/Thursday, the combination of heat and humidity will lead to heat index values approaching or even reaching into the triple digits by mid week. Daytime highs will be in the 90s with dewpoints well in the 70s, creating hot and muggy conditions. As mentioned in the previous forecast, these values are 5 to 10+ degrees above normal climatological values. With recovery efforts likely continuing into next week, please be mindful of the increasing temperatures and heat indices. Wear light- colored/light weight clothing, drink plenty of water, take frequent breaks, and remember to look before you lock! Adams && .AVIATION... (06Z TAF Issuance) Issued at 1153 PM CDT Fri May 3 2024 A much quieter night is on tap with coverage through Sat afternoon remaining spotty as well. Moderate onshore winds are going to con- tinue overnight and should help to keep ceilings somewhat elevated until closer to sunrise. Winds will be strengthening a bit more as the day progresses on Sat as CIGs mix out. S/SE winds should be in the 6-12kt range tonight...then 12-20kts/G20-25kts tomorrow after- noon (higher near the coast). Did add the mention of VCSH(for now) to IAH (and CLL) as the next storm system approaches from the west tomorrow night through Sun morning. 41 && .MARINE... Issued at 407 PM CDT Fri May 3 2024 Onshore winds have remained elevated this afternoon, remaining near 20 to 25 knots. With this expected to prevail for the next several hours, in addition to seas reaching as high as 7 feet onshore, a Small Craft Advisory remains in effect until late this evening. Winds will diminish somewhat heading into tomorrow, with moderate onshore winds expected to prevail into next week. Scattered showers and storms will be possible tomorrow, with a more widespread and well organized line of storms arriving later on Sunday. This line of storms could produce some strong wind gusts, as well as periods of heavy rain. Cady && .HYDROLOGY... Issued at 302 AM CDT Fri May 3 2024 There is ongoing river flooding over parts of Southeast Texas, particularly along portions of the Trinity and San Jacinto rivers. The following river points are at, or forecast to go to Major flood stage: - Trinity River (Madisonville): Major Flood Stage - Trinity River (Liberty): Major Flood Stage - Trinity River (Goodrich): Major Flood Stage - West Fork San Jacinto (Conroe): Major Flood Stage - West Fork San Jacinto (Humble): Major Flood Stage - East Fork San Jacinto (Cleveland): Major Flood Stage - Caney Creek (Splendora): Major Flood Stage - Trinity River (Romayor): Minor forecast to go to Major - Navasota River (Normangee): Minor forecast to go to Major - Menard Creek (Rye): Moderate forecast to Major - Trinity River (Moss Bluff): Moderate forecast to go to Major - East Fork San Jacinto (New Caney): Moderate forecast to go to Major - Peach Creek (Splendora): Moderate forecast to go to Major - San Jacinto (Sheldon): Moderate forecast to go to Major Remember to heed any instructions from your local officials and to never travel through flooded areas or roadways. Please monitor updated forecasts via the NWS AHPS website and/or the new NWS NWPS webpage (https://water.noaa.gov/) as the river flood threat continues.  JM && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 70 84 70 82 / 10 20 60 60 Houston (IAH) 72 84 72 82 / 10 10 30 50 Galveston (GLS) 73 80 73 80 / 10 10 20 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...Flood Watch through Sunday afternoon for TXZ163-164-176>179- 195>200-212>214-300-313. High Rip Current Risk through Saturday evening for TXZ436>439. GM...Small Craft Advisory until 1 AM CDT Saturday for GMZ330-335-350- 355-370-375. && $$ SHORT TERM...Adams LONG TERM....Adams AVIATION...41 MARINE...Cady ####018007056#### FXUS61 KPBZ 040503 AAC AFDPBZ Area Forecast Discussion...UPDATED National Weather Service Pittsburgh PA 103 AM EDT Sat May 4 2024 .SYNOPSIS... Intermittent rain and a few storms are possible through the weekend. With clouds and rain, temperatures will be cooler today, but will rebound Sunday as a southerly flow returns. A brief break in the rain is possible Monday. && .NEAR TERM /THROUGH TODAY/... KEY MESSAGES: - Showers taper off overnight. - Showers slowly move back over the region later this morning. - Cooler temperatures today. ------------------------------------------------------------------- Showers are expected to dissipate overnight as the weak wave riding on the backside of the east coast ridge drifts north of the region. Clouds will blanket the area and keep overnight lows well above normal. East coast ridge will move very little today and amplify this morning in response to trough digging into the northern Plains. We will continue to rest on the western side of the ridge where a shortwave will drift northward throughout the day. Deep moisture will flow northward on the backside of the ridge axis keeping in plenty of clouds and the risk for showers all day. An increasing southeasterly flow at the surface will pump Atlantic moisture into the region aiding in the shower development. For the most part, rainfall should be on the light side. HREF probs for 24 hour rainfall ending at midnight tonight for >0.25 generally range from 30 to 50% with some pockets of 60 to 70% over portions of northern WV and the higher elevations. Clouds, showers and a cool easterly flow will keep temperatures slightly below normal today. && .SHORT TERM /TONIGHT THROUGH MONDAY/... KEY MESSAGES: - Unsettled pattern remains with rain chances continuing through Sunday. Thunder possible on Sunday. - Temperatures push back above normal Sunday and Monday. ------------------------------------------------------------------- East coast ridge will flatten and drift eastward on Sunday. The shortwaves riding northward on the western flank of the ridge will also shift to the east. Shower coverage looks to dissipate Sunday morning. A weak cold front will slowly cross Ohio Sunday. Models are hinting that scattered storms could develop ahead of the front Sunday afternoon. However, ample cloud cover,limited instability, and lack of upper level support should work to shunt storm development and intensity. Temperatures will warm on Sunday as the low-level flow veers to the southwest ahead of the front. Ensembles have been consistent in showing a shortwave trough over the Middle Ohio Valley approaching, but weakening, on Monday as it interacts with a weak ridge over our region. A south-to-north gradient in PoP values still seems appropriate for the Monday/Monday night period. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... KEY MESSAGES: - Rain chances continue next week but more uncertainty lends to lower confidence. - Temperatures favored to remain above normal. ------------------------------------------------------------------- Uncertainty still reigns after Monday. Most guidance depicts a ridge centered over the Great Lakes at 12Z Tuesday, along with a deep closed upper low in or near the Dakotas. The upper low appears likely to fill during the midweek period, and as it does so, shortwaves rotating around it appear to flatten out the ridge as it moves across the Upper Ohio Valley, finally eroding it almost completely in the northeast CONUS. Some strength and timing issues remain with the details of this process, which in turn could impact precipitation amounts and timing. Nevertheless, a warm front is likely to cross on Tuesday as the ridge progresses eastward. This will lead to the persistence of a warm and moist airmass, with precipitable water values at or above the 90th percentile in the climatology. Along with the previously mentioned shortwave activity, this will keep an active weather pattern in place for our region, with decent daily precipitation chances through Friday. Deep-layer shear will increase as well behind the departing ridge, so severe weather chances will need to be monitored as well. According to CSU machine-learning guidance and NBM CWASP probabilities, Wednesday and Thursday may be the days to watch. && .AVIATION /05Z SATURDAY THROUGH WEDNESDAY/... VFR ceilings and scattered light showers are ongoing across the area this evening. Removed the mention of thunder from 00Z TAFs as instability is waning and any lingering occurrences of lightning would be brief and isolated, with little impact to area terminals. Into tonight, convection is expected to subside in coverage, with only some light lingering showers possible primarily southeast of a ZZV-PIT-DUJ line. Meanwhile, saturation from the rain and cooling temperatures may allow an MVFR cloud deck to settle in by daybreak as winds shift to southeasterly. The highest probabilities for ceiling restrictions, per the latest hi-res ensemble guidance, exist north and west of Pittsburgh, across portions of eastern Ohio and northwestern PA. East of PIT, it appears downsloping southeasterly winds may help keep low-level moisture profiles slightly less saturated and thus, mitigate the formation of widespread MVFR/IFR ceilings. Widespread rain chances increase again after 18Z Saturday. Locally lower ceilings and visibilities can be expected in the heavier showers. Continued to leave thunder out of the TAFs during that period given uncertainty surrounding how much instability will develop. If lightning does occur, the best chances according to hi-res ensembles would be southwest of PIT, so a mention of thunder at ZZV and HLG may be needed in future updates. .Outlook... Restriction potential continues through Sunday morning, with additional storm chances Sunday afternoon. Periodic restrictions may continue through early next week as multiple disturbances pass through the region. && .CLIMATE... Some record warm minimum temperatures may be approached on Saturday. Below is a table showing the latest forecasted low temperature for each climate site, their respective record value, and the year it was set. Forecast Record Year Pittsburgh 60 65 1938 Wheeling 62 63 1931, 1939, 1941 Morgantown 61 63 2021 New Philadelphia 60 60 2012 Zanesville 63 65 1902 && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...22 NEAR TERM...22 SHORT TERM...22/CL LONG TERM...CL AVIATION...Cermak/Milcarek CLIMATE...CM