Alert archive / Alaska / Areal Flood Warnings in 2021
Areal Flood Warning 2, NWS Anchorage, AK
NWS Anchorage, AK issued this areal flood warning at Apr 22, 2021, 12:56 PM AKDT. It took effect at Apr 22, 2021, 1:02 PM AKDT. It was in force for 71 hr. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Apr 22, 2021, 12:56 PM AKDT (20:56 UTC)
- In effect from
- Apr 22, 2021, 1:02 PM AKDT
- Expired
- Apr 25, 2021, 12:14 PM AKDT
- In force
- 71 hr
- Issued by
- NWS Anchorage, AK
- Area
- Storm-based polygon
- Flood severity
- None
The radar
The Kenai radar (PAHG), 109 km from the middle of the area, began a volume at 20:57 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
Anchorage Iap/Pt. Campbe, (PANC), launched 12:00Z, 8.9 hours before the alert went out and 184 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1853 m above ground
- 0-6 km bulk shear
- 10 kt
- 0-1 km storm-relative helicity
- 26 m²/s²
- 0-3 km storm-relative helicity
- 38 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
828 WGAK48 PAFC 222102 FLWAFC BULLETIN - IMMEDIATE BROADCAST REQUESTED Flood Warning National Weather Service Anchorage AK 1256 PM AKDT Thu Apr 22 2021 AKZ121-232100- /O.NEW.PAFC.FA.W.0002.210422T2102Z-210423T2100Z/ /00000.0.IJ.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Western Kenai Peninsula- 1256 PM AKDT Thu Apr 22 2021 The National Weather Service in Anchorage has issued a * Flood Warning for... An Ice Jam in... The Anchor River downstream of the Old Sterling Highway bridge. * Until 100 PM AKDT Friday. * At noon on Thursday, the river gage was reporting a stage of 17.5 feet due to an ice jam just downstream of the Old Sterling Highway. On Thursday morning, water was flowing over the campground at the Anchor River State Recreation area. There were also reports of water intermittently flowing over River Road, which is adjacent to the Recreation area. * As spring melt and breakup continues over the next few days, be prepared for fluctuating water levels and flood conditions along the Anchor River. There are numerous ice jams along the river and flooding may grow worse as the ice jams release and rejam or as new jams form. The most likely areas to experience flooding are the Anchor River Site Recreation Area, Old Sterling Highway, and River Road. PRECAUTIONARY/PREPAREDNESS ACTIONS... Turn around, don't drown when encountering flooded roads. Most flood deaths occur in vehicles. A Flood Warning means that flooding is imminent or occurring. All interested parties should take necessary precautions immediately. && LAT...LON 5979 15181 5976 15179 5975 15184 5978 15185 $$ Lawson
3 follow-up statements
778 WGAK48 PAFC 231800 FLWAFC BULLETIN - IMMEDIATE BROADCAST REQUESTED Flood Warning National Weather Service Anchorage AK 952 AM AKDT Fri Apr 23 2021 AKZ121-252100- /O.EXT.PAFC.FA.W.0002.000000T0000Z-210425T2100Z/ /00000.0.IJ.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Western Kenai Peninsula- 952 AM AKDT Fri Apr 23 2021 The National Weather Service in Anchorage has extended the * Flood Warning for... An Ice Jam in... The Anchor River downstream of the Old Sterling Highway bridge. * Until 100 PM AKDT Sunday. * At 1000 AM AKDT, the river gage was reporting a stage of 16.5 feet due to an ice jam just downstream of the Old Sterling Highway. At the Anchor River State Recreation Area, water levels have been dropping and water is no longer flooding the Anchor River Road or campground, but this is subject to change as the ice jam shifts and more ice is added from upstream. * There is also an ice jam in place near mile 162 of the Sterling Highway, just south of Anchor Point. On Friday morning water was not yet flowing over the Sterling Highway, however, river levels could still rise due to rain, snowmelt, or a shifting ice jam. * As spring melt and breakup continues over the next few days, be prepared for fluctuating water levels and flood conditions along the Anchor River. There are numerous ice jams along the river and flooding may grow worse as the ice jams release and rejam or as new jams form. PRECAUTIONARY/PREPAREDNESS ACTIONS... Turn around, don't drown when encountering flooded roads. Most flood deaths occur in vehicles. A Flood Warning means that flooding is imminent or occurring. All interested parties should take necessary precautions immediately. && LAT...LON 5979 15181 5976 15179 5975 15184 5978 15185 $$ Lawson
678 WGAK88 PAFC 241936 FLSAFC Flood Statement National Weather Service Anchorage AK 1121 AM AKDT Sat Apr 24 2021 AKZ121-252100- /O.CON.PAFC.FA.W.0002.000000T0000Z-210425T2100Z/ /00000.0.IJ.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Western Kenai Peninsula- 1121 AM AKDT Sat Apr 24 2021 ...A FLOOD WARNING FOR AN ICE JAM REMAINS IN EFFECT UNTIL 100 PM AKDT Sunday along the Anchor River downstream of the Old Sterling Highway Bridge... At 1121 AM AKDT, the fire department reported that the ice jam had released from the bridge along the Old Sterling Highway and had moved to the area between Silverking and Coho campgrounds. The Silverking campground is completely flooded, including the parking lot while the Coho campground is flooded, not including the parking lot. Water was also observed flowing over the highway between the two campgrounds for around 150 ft, 6 inches deep. Ice debris has been observed at both campgrounds as well as over the highway. The river gage is reporting minor flood stage of 15.8 ft, but has continued to fall due to the ice jam moving downstream. As spring melt and breakup continues over the next few days, be prepared for fluctuating water levels and flood conditions along the Anchor River. There are numerous ice jams along the river and flooding may grow worse as the ice jams release and re-jam or as new jams form. PRECAUTIONARY/PREPAREDNESS ACTIONS... Turn around, don't drown when encountering flooded roads. Most flood deaths occur in vehicles. A Flood Warning means that flooding is imminent or occurring. All interested parties should take necessary precautions immediately. && LAT...LON 5979 15181 5976 15179 5975 15184 5978 15185 $$ Lawson
179 WGAK88 PAFC 252016 FLSAFC Flood Statement National Weather Service Anchorage AK 1214 PM AKDT Sun Apr 25 2021 AKZ121-252024- /O.CAN.PAFC.FA.W.0002.000000T0000Z-210425T2100Z/ /00000.0.IJ.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Western Kenai Peninsula- 1214 PM AKDT Sun Apr 25 2021 ...THE FLOOD WARNING FOR AN ICE JAM HAS BEEN CANCELLED FOR the Anchor River downstream of the Old Sterling Highway Bridge... The flood water is receding. Therefore, the flooding threat has ended. LAT...LON 5979 15181 5976 15179 5975 15184 5978 15185 $$ Kobold
What forecasters said that day
The local office's own words before this areal flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Anchorage, AK wrote its last area forecast discussion before this areal flood warning went out at Apr 22, 4:39 AM AKDT, 8 hours 17 minutes earlier.
Area forecast discussion, Apr 22, 4:39 AM AKDT, 8 hours 17 minutes before
Southcentral and Southwest Alaska Forecast Discussion National Weather Service Anchorage AK 439 AM AKDT Thu Apr 22 2021 .ANALYSIS AND UPPER LEVELS... Strong high pressure remains over the Interior, with upper level ridging extending across the Gulf and into the North Pacific. Meanwhile, multiple lows, troughs, and fronts move across the Bering over the next couple days. The AKPen, Aleutians, and Kodiak Island will see the most active weather as the strong high pressure blocking pattern keeps any frontal systems from pushing across the Mainland. && .MODEL DISCUSSION... Models are in good overall synoptic agreement. There are a few discrepancies regarding the low center(s) within the system just south of the Aleutians today. The models are handling a second North Pacific low approaching the Aleutians this weekend quite well. Overall strength, track, and timing seem to be in alignment across the models, with the fairly significant differences in center location. The NAM is much further north and west than the remaining models, even crossing into the Bering while the rest stay south of the Chain. The GFS enters the Bering shortly after, still tracking south of the NAM however, while the Canadian/EC solutions stay south of the Chain through the weekend. && .AVIATION... PANC...VFR conditions and light winds will persist. && .SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)... It is a very similar pattern today as was the case yesterday over Southcentral. The front is over Kodiak Islands and extends southeast from there through the Gulf of Alaska. This front is having a difficult time moving any farther north due to the strong ridge over the Interior of the state. The rain is stalling out over Kachemak Bay early this morning and may just nudge a little farther northward today before the ridge builds back over Southcentral tomorrow and brings sunshine to all of Southcentral. Kodiak will see continued heavy rain at times today with the front stalled over them. Kodiak Airport set a record yesterday for daily rainfall at 1.49 inches. The rain should lessen in intensity this evening and then finally move completely out of the area Friday night. && .SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3: Today through Saturday)... A relatively quiet, drier weather will persist as a result of a persistent high pressure over the State. Subsidence dry air and warm mid-level temperatures over Southwest Alaska will reduce the potential for rain activity across Y-K Delta and the lower Kuskokwim Valley. Meanwhile, tropical moisture combined with east- northeast flow over Bristol Bay and AKPEN will increase the potential for rain showers there today and tonight before conditions begin improving Friday morning. && .SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3: Today through Saturday)... A fixed North Pacific low remains to be the driving weather mechanism for the Aleutians and part of the Bering Sea until it tapers off early Friday morning. Elevated seas and winds along the central Aleutians will gradually diminish tonight reflecting the weakening low until the next North Pacific low reaches the central Aleutians Friday afternoon. The next system will bring gale conditions and elevated seas and swells through the weekend, with more widespread rain passing through central and eastern Aleutians and Pribilof Islands in the next couple days. && .MARINE (Days 3 through 5/Saturday through Monday)... A North Pacific low tracks over the Southern Bering through Sun before crossing back into the North Pacific by Mon. How far north it will track and its development of this storm are uncertain. Small craft winds are likely to wrap the low through Mon, with local gale force winds over the Eastern Aleutians, particularly near channeled terrain on Sat. Generally light winds over the Gulf through mid-day Sun when high pressure brings gusty westerly winds less than small craft over the Northern Gulf late Sun into Mon. && .LONG TERM FORECAST (Days 4 through 7/Sunday through Wednesday)... A blocking ridge that is the dominant feature over most of the mainland will attempt to be pushed towards the Bering late this weekend and towards the early part of next week. The latest deterministic and ensemble guidance is indicating that a strong polar low will work south across Canada, shoving the high pressure bubble to the west as it weakens. The global forcing responsible for much of our abnormal weather (MJO) is weakening and that will start to trend the area back to normal weather for late April. The Anchorage Bowl should still see 'mild' afternoons in the mid 50s, while inland areas in the MatSu will soar into the 60s. Monday through Wednesday will see daytime highs slowly drop from the mid 50s to upper 40s. As for any rain chances? It's panning out to be dry through next week for all areas along the coast and inland. && .AFC WATCHES/WARNINGS/ADVISORIES... PUBLIC...Flood Warning 121 (Anchor River) MARINE...Gale Warning 131 FIRE WEATHER...NONE. && SYNOPSIS AND MODEL DISCUSSION...KM SOUTHCENTRAL ALASKA...EZ SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...CB MARINE/LONG TERM...MK/SS
The office that day
Everything else NWS Anchorage, AK issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 21, 4:05 PM AKDT | Gale Warning | AFC | 11 hr | |
| Apr 21, 4:05 PM AKDT | Small Craft Advisory | AFC | 24 hr | |
| Apr 22, 3:14 AM AKDT | Small Craft Advisory | AFC | 5 days | |
| Apr 22, 3:18 AM AKDT | Small Craft Advisory | AFC | 13 hr | |
| Apr 22, 3:59 PM AKDT | Gale Warning | AFC | 47 hr | |
| Apr 22, 3:59 PM AKDT | Small Craft Advisory | AFC | 12 hr |
Nearby
Areal Flood Warnings in Alaska, 2021Every areal flood warning in 2021
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.