Weather
KCRG TV9 First Alert Forecast For Dubuque and the Tri-States
KCRG TV9 FIRST ALERT FORECAST FOR FRIDAY, JANUARY 18, 2019
WINTER STORM WARNING IN EFFECT FROM NOON TODAY UNTIL NOON SATURDAY.
TODAY: CLOUDY WITH SNOW DEVELOPING THIS AFTERNOON AND TURNING WINDY.
HIGH 25. NORTHEAST WIND 10-20 MPH.
TONIGHT: CLOUDY AND WINDY WITH SNOW, HEAVY AT TIMES. LOW 15. NORTHEAST
WIND 15-30 MPH.
TOMORROW: SNOW ENDING BY MID-MORNING. WINDY WITH AREAS OF BLOWING SNOW.
STORM TOTAL OF 6-9” POSSIBLE. HIGH 16. NORTH WIND 15-25 MPH.
EXTENDED OUTLOOK SUNDAY THROUGH TUESDAY:
DRY AND VERY COLD SUNDAY, A CHANCE OF SNOW MONDAY INTO TUESDAY HIGH’S IN THE SINGLE DIGITS SUNDAY, THE TEEN’S MONDAY, THE 20’S TUESDAY. LOW’S IN THE SINGLE DIGITS BELOW ZERO SUNDAY AND MONDAY, THE TEEN’S TUESDAY.
MISSISSIPPI RIVER STAGE AT DUBUQUE: 10.5-FEET & RISING
KCRG Weather Blog
Freezing drizzle explained
It's our number one question right now: Why isn't it snowing? It's cold enough to do so, but won't. It all has to do with how the atmosphere is layered and where things are saturated. Snowflakes will grow when temperatures are between -10C and -20C, which is 14F to -4F. Anything outside of that range is very small plates, needles, or nothing at all. In our case, the snow growth zone (technically called the Dendritic Growth Zone) is void of saturation, meaning there's no moisture to form snowflakes. So in this case, no matter what the surface temperature, we will not have decent snowflakes today. I have circled that dry layer in the weather balloon image from this morning, launched by NWS. Instead, we are saturated in the lowest kilometer or so of the atmosphere. Lines that are close together depict this. This is enough to allow for drizzle drops to develop. Because there isn't much of anything to condense to (called Cloud Condensation Nuclei), these drops are staying as drops despite it being below freezing. This saturated layer is also circled. This layer is also nowhere near the snow growth layer in this case, keeping things as drizzle drops. These drops slowly fall to Earth then and freeze on contact to everything. I mean everything. Right down to your lenses on your eyeglasses. Freezing drizzle leaves a very thin coating behind and is difficult to detect on radar due to the shallow nature of it. Freezing drizzle is the most common when snow is already on the ground as that traps the coldest air near the surface and allows for faster saturation. This will not be the last of the drizzle this year as plenty of snow and cold is on the way this weekend.
Coldest lows this season haven’t been very cold
Arctic air hasn’t had much luck staying in the Midwest so far this season. Compared to other years, the lack of really cold air is noteworthy. Cedar Rapids’ coldest low since November 1 is 6 degrees. That is the third-highest low temperature on record for the season so far. In the winter of 1913-14, the coldest temperature through January 9 was 13 degrees. 1907-08 and 1954-55 tied at 10 degrees. In Dubuque, the coldest low has been 9 degrees. That’s good for second-place, behind 1913-14. To-date in that season, the coldest low was 15 degrees. Iowa City is tricky since the data there aren’t tied together as well as our other big four cities. At the airport, the coldest low this season is 7 degrees, which is the highest on record (out of 23 years). The observation site at the treatment plant goes back to the 1890s, and its low of 5 degrees is 5th-coldest. 1907-08 checks in at 9 degrees, as does 1974-75. Next is 8 degrees in 1913-14, followed by 7 degrees in 1997-98, then 6 degrees in 2001-02. Waterloo’s coldest low is lower than elsewhere at 1 degree. However, it still ranks up there as the 5th-warmest low by this time. Winter of 1913-14 shows up again in first place with 11 degrees, followed by 6 degrees in 1907-08, 4 degrees in 2011-12, and 2 degrees in 1947-48.
Winter’s chill still largely absent
November kicked off winter with unusually chilly weather, but December pulled back in terms of temperature and wind chill. January is typically our coldest month, though winter’s chill was absent in the first week. Going back to November 1st, the coldest wind chills across eastern Iowa have only been in the -2 to -7 range. The lack of snowpack also plays a role, because the air hasn’t gotten as cold as it otherwise could be. While there is some cold air coming Tuesday tonight into Wednesday, it’ll only generate wind chills a few degrees below zero over northern Iowa for a short time and that’ll be it. Temperatures rise back above normal going into the weekend through at least the first half of next week.
More snow will come… eventually
The overall lack of snow this season, along with the relatively mild temperatures that have been in place for the past several weeks, may have you wondering if we’re skipping over winter altogether. Since we’re only a week into January, there’s still a lot of winter to go. The least amount of snow to fall after January 7 in Cedar Rapids was 3.0” in 1934; the most was 46.5” in 1951. Only four years had less than six inches of snow fall from here through the rest of the season. The vast majority of years tallied up at least a foot of additional snowfall. In Dubuque, the lowest snowfall total after January 7 was 4.3” in 1942. That’s the only year to get less than six inches to finish off the season. Only 10 years since the 1893 have had less than a foot of additional snow. 2008 picked up the most snowfall with 55.6” after January 7. For Iowa City, 2006 had the least snowfall after January 7 with 4.0”. 1905 and 1912 are a tie for the most at 41.0”. Six years had less than 6” of additional snow, but the past two seasons are among them! 2017 finished the season with 4.7”, and 2016 had 5.0”. Waterloo’s lowest snowfall after January 7 was in 1922 when a mere 2.0” fell. The most was in 1993 with 41.5”. Just like other places in eastern Iowa, getting less than 6” of additional snow is rare, happening only six times.
January grilling weather doesn’t come often
As highs look to push to the lower 50s on Saturday, this gives an opportunity to look back in history to see how often this happens around eastern Iowa. A “January thaw” occurs quite often with brief bouts of mild weather in the 40s and sometimes 50s, though it can be accompanied by clouds and fog or gusty winds. Reaching 50 or more on any given day has low odds. The chance is only 1% on January 1st and rises to around 5% by the end of the month. In January 2002, Cedar Rapids got to 50 or better nine times!