April

National Weather Service Grand Forks

Weather & Climate Review

April-May 2020

Table 1 April 2020 Temperature and Precipitation Statistics

Figure 1

April Daily

Departure from

Normal

Temperatures at

Fargo, ND

Blue Bars = Colder than Normal Days & Red Bars = Warmer than Normal Days

Table 1 shows the April average temperature (AveT), departure from normal temperature (TDept), precipitation (Pcpn), departure

from normal precipitation (PDept), and snowfall (Snow) for our 5 main climate sites (Devils Lake (DVL), NWS Grand Forks (NWS GF),

Fargo (FAR), Baudette (BDE), and Park Rapids (PKD)). The April average temperature was colder than normal at all sites, but coldest

at Devils Lake (-7.8 degrees). Precipitation amounts were above normal at NWS Grand Forks and Fargo, but below normal at Bau-

dette and Park Rapids. Figure 1 plots the daily departure from normal temperatures in April 2020 at Fargo, ND. Generally the begin-

ning and ending of the month featured above normal days, while the middle part of the month had below normal days.

At Fargo on April 2nd, the daily precipitation amount of 0.98 inches and the daily snowfall amount of 4.8 inches set

new records. On April 14th, the high of 26 set a new record low maximum. Records

Figure 2 April Observed Precipitation Figure 3 April Percent of Normal

Table 1 only gives observed precipitation for 5 sites, which does not cover much of eastern North Dakota and the northwest quar-

ter of Minnesota. Therefore Figure 2 is included, which gives an estimate for the entire area. Looking at the color scale on the right

of Figure 2, most of eastern North Dakota and the northwest quarter of Minnesota received one to three inches of precipitation

(darker greens and yellow colors). Less precipitation fell from Baudette to Bemidji to Park Rapids (light green color, or 0.50 to 1.00

inches). Figure 3 shows the April precipitation as a percent of normal. This makes it easier to see how areas east of the Red River

Valley were a little drier than normal. Table 1 also showed the below normal precipitation amounts at Baudette and Park Rapids.

FARGO FARGO

Temperature Precipitation

Figure 4 CPC Temp Outlook Figure 5 Observed Temp Figure 7 Observed Pcpn

The April temperature (Figure 4) and precipitation (Figure 6) outlooks issued by the Climate Prediction Center (CPC) in late March

are shown above. Compare these with the observed April departures from normal temperatures (Figure 5) and precipitation

(Figure 7).

Figure 8 Monthly Departures from

Normal Temps at Fargo, ND Figure 9 Monthly Departures from

Normal Pcpn at Fargo, ND

Figure 8 shows that April 2020 was the coldest month of the past six

(compared to normal) and only January was warmer than normal.

Figure 9 shows that after three drier than normal months (January,

February, and March), April 2020 was slightly wetter than normal.

Looking at just the Fargo climate site (FAR), Figures 8 and 9 show how April 2020 fits into the previous 5 months. Fig-

ure 8 plots the monthly departures from normal temperatures at Fargo. The blue bars represent months that were

colder than normal, while the red bars represent months that were warmer than normal. Figure 9 plots the monthly

departures from normal precipitation at Fargo. The green bars represent months that were wetter than normal, while the brown

bars represent months that were drier than normal.

Winter Warning

6 Month

Trend

Figure 6 CPC Pcpn Outlook

Figure 10 April 1-3

Winter

Storm

Warning

Figure 11 Snow Totals (April 1-3)

Convective & Red Flag Warnings

Figure 12 April 2020 Convective Warnings

Red Flag

Warning

Figure 13 April 20 Red Flag Warning

Although April is usually early for

severe convective weather, 4 Se-

vere Thunderstorm Warnings were

issued, all on the 7th (Figure 12). A

series of storms tracked from

northern Richland County (ND)

toward Wadena (MN). A user re-

quested Red Flag Warning was

issued for Grant County (MN) on

April 20th, mainly for dry fuels.

One Winter Storm Warning was issued in April (Figure 10),

which brought most of the precipitation for the month. Figure

11 shows the snowfall totals from the event. This is the main

reason Figures 2 and 3 from the previous page look the way

they do (not much snow fell from Baudette to Park Rapids).

The latest Climate Prediction Center (CPC) temperature (Figure 16) and

precipitation (Figure 17) outlooks for May are shown to the left. For east-

ern North Dakota and the northwest quarter of Minnesota, the CPC is

forecasting equal chances for above, normal, or below normal tempera-

tures. For precipitation, half of the area is covered by equal chances and

half of the area is covered by higher probabilities for below normal pre-

cipitation. Figure 16 Temperature Figure 17 Precipitation

May

Last Year

&

Normals

May 2019 was a slightly colder and mainly drier than normal month. Table 3 shows that departure from normal

temperatures ranged from 3.3 degrees below normal at NWS Grand Forks to 6.1 degrees below normal at Devils

Lake. All sites except Fargo ended with below normal precipitation. May 2019 had two days with busy convective

weather (Figure 18), the 15th and the 24th. Fifteen severe thunderstorm warnings were issued on the 15th, but 5

tornado warnings were issued on the 24th.

Table 3 May 2019 Temperature and Precipitation Statistics

River Flooding

Table 2 Preliminary Red River Crest Information

Figure 14 Red River Width April 16th

Grand Forks

Figure 15 Highest Flood Category for all Forecast Points

The spring flood occupied most of April

2020. Some river points (mainly from

Grand Forks southward) experienced dou-

ble crests. Table 2 shows preliminary crest

information for Red River points (the

USGS determines the final crest numbers).

The worst flooding was north of Grand

Forks, which was evident on visible satel-

lite imagery (Figure 14). Finally, Figure 15

shows the highest flood category for all

river forecast points.

Figure 18 May 2019 Convective Warnings

EC B

Miscellaneous

Figure 19 Normal Temps May 1

Figure 22 May 2019 Data

Figure 20 Normal Temps May 31 Figure 21 Normal May Pcpn

As a comparison to normal values, Figure 22 shows various observed

data from last year (2019). As an example, in Fargo (FAR), 2.90 inches of

precipitation (green box) fell. The highest temperature was 91 degrees

(red number), while the lowest temperature was 24 degrees (blue num-

ber).

The winning picture in our April photo contest was a bobcat (Page 1, top right). Figure 23 shows an interesting occurrence from

April 21st and Figures 24 and 25 show pictures during the April 2nd Winter Storm.

So what are normal temperatures in May? Figure 19 shows normal highs and lows on May 1st for selected cities across eastern

North Dakota and northwest Minnesota. Figure 20 shows how normal highs and lows change by May 31st. As an example, at NWS

Grand Forks on May 1st, the normal high is 63 and the normal low is 38. By May 31st at NWS Grand Forks, the normal high rises to

73 and the normal low rises to 49. Figure 21 shows the normal precipitation amounts at the same sites as Figures 19 and 20. As an

example, the normal precipitation at NWS Grand Forks in May is 2.75 inches.

Figure 23 Interesting Phenomena on April 21st

Figure 24 Large snowflakes on April 2nd

Figure 25 Footprint on April 2nd